OzVMX Forum
Marque Remarks => Honda => Topic started by: Kenneth S (222) on January 19, 2013, 08:13:16 pm
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Hi Guys,
Does anyone know a source for wide footpegs for this model?
I also find the front break lever sits too far out and there is no adjustment to it. Was it stock this way? Is there a good solution you have come across for this to make it adjustable or at least sit closer to the grip?
Thanks,
Ken
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send your existing pegs to GMC - not only will they come back wide but then bolt straight on!
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Ken, I got a set of these on ebay recently
http://www.ebay.com/itm/280919421622?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
The price was right even though the shiping cost is over the top. They took a bit of modifying to fit my 82 CR125 though, had to mill 1mm from either side to fit the frame, drill out the hole for the pin and drill some holes for the return spring but overall they're not to bad,
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Ken, I got a set of these on ebay recently
http://www.ebay.com/itm/280919421622?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
The price was right even though the shiping cost is over the top. They took a bit of modifying to fit my 82 CR125 though, had to mill 1mm from either side to fit the frame, drill out the hole for the pin and drill some holes for the return spring but overall they're not to bad,
Cheers for that
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I also find the front break lever sits too far out and there is no adjustment to it. Was it stock this way? Is there a good solution you have come across for this to make it adjustable or at least sit closer to the grip
Drill a hole and tap a 6 mm thread through the front of the perch so you can put an allen key screw/bolt in that acts as a stop/adjuster for the lever
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I also find the front break lever sits too far out and there is no adjustment to it. Was it stock this way? Is there a good solution you have come across for this to make it adjustable or at least sit closer to the grip
Drill a hole and tap a 6 mm thread through the front of the perch so you can put an allen key screw/bolt in that acts as a stop/adjuster for the lever
Excellent! Thanks. So bloody obvious :-\
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I also find the front break lever sits too far out and there is no adjustment to it. Was it stock this way? Is there a good solution you have come across for this to make it adjustable or at least sit closer to the grip
Drill a hole and tap a 6 mm thread through the front of the perch so you can put an allen key screw/bolt in that acts as a stop/adjuster for the lever
Barsby was wrong then.....you do have some use
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I also find the front break lever sits too far out and there is no adjustment to it. Was it stock this way? Is there a good solution you have come across for this to make it adjustable or at least sit closer to the grip
Drill a hole and tap a 6 mm thread through the front of the perch so you can put an allen key screw/bolt in that acts as a stop/adjuster for the lever
Barsby was wrong then.....you do have some use
That's it though. He just peaked!
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I also find the front break lever sits too far out and there is no adjustment to it. Was it stock this way? Is there a good solution you have come across for this to make it adjustable or at least sit closer to the grip
Drill a hole and tap a 6 mm thread through the front of the perch so you can put an allen key screw/bolt in that acts as a stop/adjuster for the lever
Barsby was wrong then.....you do have some use
That's it though. He just peaked!
The sad thing is, I think Vandy gave me this tech tip a few yrs ago
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late model ktm ;)
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I also find the front break lever sits too far out and there is no adjustment to it. Was it stock this way? Is there a good solution you have come across for this to make it adjustable or at least sit closer to the grip
Drill a hole and tap a 6 mm thread through the front of the perch so you can put an allen key screw/bolt in that acts as a stop/adjuster for the lever
Barsby was wrong then.....you do have some use
That's it though. He just peaked!
The sad thing is, I think Vandy gave me this tech tip a few yrs ago
I will retract my statement then............you remain useless
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A little trick that got done to my CZ at 1 stage to move the lever closer to the bars was a cable tie looped around the perch somewhwere between the cable & pivot, works the same as the screw without weakening the perch
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I like it! An easy fix.
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Get a shorty style lever Ken? I did that and the lever sits a lot closer as it's shaped towards the grip.
Hey where's the frame mate?? I am ready to do it for you mate !! You dropping it off this weekend? :)
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Get a shorty style lever Ken? I did that and the lever sits a lot closer as it's shaped towards the grip.
Hey where's the frame mate?? I am ready to do it for you mate !! You dropping it off this weekend? :)
Hey Dave,
Can't find a shorty for this model. There must be an embargo on them I'm not aware of.
If I don't make it up to you over the weekend, I'll ship the frame up next week by Toll.
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Kenneth,
These are the shorty style levers, this is a brake the same seller also has clutch levers and similar ones in matt black
I normally buy two sets so I have spare levers/perch's it also helps rationalise the shipping cost
http://www.ebay.com.au/itm/Universal-Brake-Lever-Perch-Assembly-Honda-CR-CRF-XR-XL-/280963365939?pt=Motorcycles_Parts_Accessories&hash=item416ab8bc33
Regards
Peter
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Get a shorty style lever Ken? I did that and the lever sits a lot closer as it's shaped towards the grip.
Hey where's the frame mate?? I am ready to do it for you mate !! You dropping it off this weekend? :)
Cool! 8) Hardo's frame services! I have a few here to do mate!
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LOL .... I am gunna chop it up into 30 pieces Ando..... jus' to slow him down a bit this year.... :P
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Kenneth,
These are the shorty style levers, this is a brake the same seller also has clutch levers and similar ones in matt black
I normally buy two sets so I have spare levers/perch's it also helps rationalise the shipping cost
http://www.ebay.com.au/itm/Universal-Brake-Lever-Perch-Assembly-Honda-CR-CRF-XR-XL-/280963365939?pt=Motorcycles_Parts_Accessories&hash=item416ab8bc33
Regards
Peter
Hi Peter,
Thanks for this, they look spot on for my 79 model. The 84 has the disc brake though and I have struggled to find a shorty to fit.
Cheers,
Ken
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Here ya go Ken,MCS do a shorty lever,I've got one on my 85 125,They are a nice feeling shape, Only a cheap taiwanese job though,I.E. very brittle ;)
You could also heat your original lever & very carefully bend it to suit,that seems to work on most good quality O.E.M. levers :)
http://www.mcsonline.com.au/index.php?option=com_virtuemart&page=shop.product_details&flypage=garden_flypage.tpl&category_id=184&product_id=2077&Itemid=126
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Here ya go Ken,MCS do a shorty lever,I've got one on my 85 125,They are a nice feeling shape, Only a cheap taiwanese job though,I.E. very brittle ;)
You could also heat your original lever & very carefully bend it to suit,that seems to work on most good quality O.E.M. levers :)
http://www.mcsonline.com.au/index.php?option=com_virtuemart&page=shop.product_details&flypage=garden_flypage.tpl&category_id=184&product_id=2077&Itemid=126
Thanks smed, that looks spot on.
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The million dollar question Ken have you stopped it from boiling the kettle yet?
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He has it stripped down to its frame at the moment Scrivo.... so I'd say no. :o
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If it's stripped to the frame then it won't be able to boil the kettle for a while ::)
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The million dollar question Ken have you stopped it from boiling the kettle yet?
Hey Scrivo, Not sure yet. Bought a new barrel for it which is at Greg Ball's being checked over before I put humpty dumpty back together again.
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I think you deserve some sort of commendation for sticking with bike as long as you have Ken. A perserverance award or some such thing.
Most people would have gone out and bought a 250 L by now but you've stuck with it.
Well done! :)
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http://www.powersportspro.com/pages/OemParts?aribrand=HOM#/Honda/CR250R_A_(84)_MOTORCYCLE%2c_JPN%2c_VIN%23_JH2ME030-EC600001_TO_JH2ME030-EC607757/WATER_PUMP/CR250R-84-JPN-A/2Y14KA4EKA48E0400E
Ken,A mate has a CR250RE,He has the same problem and like you has tried everything,surfacing the head & cylinder,stock & aftermarket head gaskets,new rad cap,new hoses,A different head & cylinder & even new radiators,but still no good,It still boils its ass off!
In the parts diagram #5 is a tin plate with a cone shape with a hole in the middle to draw the coolant in that fits snugly over the impeller, it goes in between the two gaskets,for some reason it is not listed in the price list only on the diagram,My mate's bike does not have one & i'm wondering if that's the problem,My 85 125 has one & I can see how it would not work properly without it :)
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Item 5 appears to be an impellor shield which if missing would cause serious pump cavitation. It basically forms the pump circuit directing fluid to the centre of the impellor. I think you are onto something there Smed.
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sounds like Smed is on the money.
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that water separator is not for the re 84 but for the rf 85
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http://www.powersportspro.com/pages/OemParts?aribrand=HOM#/Honda/CR250R_A_(84)_MOTORCYCLE%2c_JPN%2c_VIN%23_JH2ME030-EC600001_TO_JH2ME030-EC607757/WATER_PUMP/CR250R-84-JPN-A/2Y14KA4EKA48E0400E
Ken,A mate has a CR250RE,He has the same problem and like you has tried everything,surfacing the head & cylinder,stock & aftermarket head gaskets,new rad cap,new hoses,A different head & cylinder & even new radiators,but still no good,It still boils its ass off!
In the parts diagram #5 is a tin plate with a cone shape with a hole in the middle to draw the coolant in that fits snugly over the impeller, it goes in between the two gaskets,for some reason it is not listed in the price list only on the diagram,My mate's bike does not have one & i'm wondering if that's the problem,My 85 125 has one & I can see how it would not work properly without it :)
Well f...k me swinging!!!
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what type of head gasket are you using i use original type from back in 84 how is the inside of your water pump clutch cover? has it been repaired ,i have devconed mine but have a nos cover to make it the right shape that could be your problem if its not shaped right you would get cavitation {air bubbles } and it would not pump the coolant very good
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You cannot cause cavitation without inducing an air source or starving it of fluid. The shape of the pump housing will not do that alone.
That thin metal sheath mentioned above by smed is well worth investigating though Ken ! :)
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you dont need air for cavitation a pressure differance eg negitive pressure can cause it. i will repeat the 84 cr 250 dose not use the separator plate check the parts book its for the 85 rf
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Ooookay... so how does "Air Pressure" differential not equal "air" ?
I maintain Boeing 737 Hydraulic and Nitrogen systems and have done so for 24 years - so I believe I understand what causes cavitation. :)
It's actually called "Starvation" - of which I dont believe is Ken's issue here.
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Ooookay... so how does "Air Pressure" differential not equal "air" ?
I maintain Boeing 737 Hydraulic and Nitrogen systems and have done so for 24 years - so I believe I understand what causes cavitation. :)
It's actually called "Starvation" - of which I dont believe is Ken's issue here.
I hope they are not green and chain driven...hehe
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Hardo cavitation can happen in a closed system as the pump pulls the gasses out of the fluid and then starts destroying the pump itselfs. I have seen pumps after cavitation that has been caused by restricted inlet resulting in low flow, starvation as you suggest, then the the pump starts to surge in power consumption and does serious pump damage. The impellor is literally pulled apart.
Although in this case cavitation is, as you say, the wrong term more like the pump bypasses because the fluid is not directed across the impellor correctly either way I agree that the impellor sheild if that is the right name is important I would think.
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i have seen the same thing happen to sea doo jetpumps when the clearance is to large between the wear ring and impellor i was tought that it was cavitation at the sea doo trainning so its called starvation ,if he has a 84 re it is not made to have a separator plate puting one in could damage the impellor my question is has the water pump cover been repaired and if not is it damaged ,if the cover is as it should be then its not made for a separator plate the 85 rf has this plate but the rf has a different cover, i agree with montynut that if the cover is damaged or been repaired that the coolant is not being pumped corectly because of the shape of the cover
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Thanks for bringing this up Smed. I have considered that perhaps there is no leak into the cooling system and the bike is simply over heating for another reason and this could uncover that reason.
The pump cover itself is in pretty good condition, but...the side cover has corrosion all through it, has been devconned to seal where it corrodes through and the interior of the side cover where the impeller is, is a pitted mess. There is enough clearance for the impeller but the surface of the side cover side of the impeller chamber is nothing like it would have been when it was stock.
I am using a Toyota coolant which has great corrosion inhibiting characteristics but I have wondered as that coolant was designed for the cooling systems of cars, not vintage dirt bikes, whether the abrupt nature of pumping the coolant through the dirt bike system was causing the coolant to behave in an odd way. If the inner surface of the impeller chamber is causing starvation or cavitation then perhaps the characteristics of this coolant could be contributing to the problem.
Mont, thanks for your comments. Its all about how you perceive your lot isn't it? When I finally do resolve this, it will make whatever result I get all the more sweeter knowing I turned this steaming kettle, which had been badly neglected over the years, back into a proper race bike.
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Kenneth, The type of coolant is not the problem. Even if you used neat water it will do the same thing.
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Hey Kenneth,
From an autmotive engine reconditioner & mechanic's perspective ( in a previous life), in no particular order.
Blockages/flow restrictions in radiator.
Blocked or restricted radiator airflow capacity.
Coolant flowing through radiator to quickly ie removal of themostat, if this was done recomended just cutting the centre out of the themostat so water was slowed sufficently to cool in radiator before rentering engine.
Pressure loss, obviously causing some coolant loss but also not maintaining the pressurised increased boiling point, see also radiator cap not holding prescribed pressure.
Combustion gas entry into cooling system, can be detected by a TK Dye check which changes colour in the presence of CO.
Cooling system capacity not meeting engines cooling requirements. Commonly seen with modified engines with significant performance increases necesitating larger radiator & better radiator airflow.
Stupid things like blocked/restricted exhaust, too lean mixture, incorrect ignition timing.
As was mentioned above water pump cavitation, generally caused by either corrision of water pump impeller or corosion of area where water pump impeller runs ie to larger a gap or too much tubulence.
Themostat issues, jamming not opening at prescribed temp, openning intermitently.
Cheers
Stewart
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Hi Ken, could you remove the pump cover and post up some happy snaps of it inside and out, also of the impeller and housing as still assembled on the bike please. Do us a little favor first though when removing the cover. Put some "Plasticine" over the impeller and screw the cover back down firmly first. Then remove it, dissect it, and observe and measure the crushed thickness created by the impeller vanes please.
Oldstuff's diagnostic out line obviously comes from industry trained experience and is a pretty good outline for diagnostics on any liquid cooled internal combustion Engine.
Have you correctly tested or replaced the thermostat? or tryed one with the guts removed to see if it offered an measurable increase in operation time before the steam appears?
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It could be in some cases that the clutch gasket is the wrong thickness and stoping the impeller from turning ,I think thats what mickde is asking and getting you to check.
I have been caught out twice where diffrent or home made gaskets were made ;D and made internal parts stop turning freely kick starter shalfs etc etc.
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The pump cover itself is in pretty good condition, but...the side cover has corrosion all through it, has been devconned to seal where it corrodes through and the interior of the side cover where the impeller is, is a pitted mess. There is enough clearance for the impeller but the surface of the side cover side of the impeller chamber is nothing like it would have been when it was stock.
Correct me if I'm wrong here Ken but haven't you changed the whole clutch side cover already? If so, did it have the same boiling characteristics regardless of which side cover you had fitted?
If sCheers
Craig
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Have you correctly tested or replaced the thermostat? or tryed one with the guts removed to see if it offered an measurable increase in operation time before the steam appears?
Not sure these bikes have a thermostat. I've just finished building my second water cooled 82 CR and it certainly didn't have one unless it's hidden somewhere inside a higher parts assembly.
Love your tenacity Ken, this must be the most talked about issue over the past 12 months, lots of good input & info for those observing from the sidelines. Even Greg Ball spoke of your plight last time I was at his workshop.
By the way as crs and rms said the separator is for models from 85 onwards but they are available at:
http://www.partzilla.com/parts/detail/honda/HP-19222-KA4-770.html
for $6.35 + $12 shipping or even from your local dealer. Might be worth the $20 to bolt one in and take it for a run just in case....
Regards
Peter
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Hi guys, thanks again for your comments. I don't dare say it but I might have stumbled across the latest problem in the cooling system for this bike. I say latest because as Craig says, I am on the second cover for this bike as the first one was falling apart and this problem precedes this cover. When pulling the cover off today, I noticed the mechanical seal didn't seem to be seated properly. Upon closer inspection it appeared to have rotated. When I took it out, there were wear marks on the inside of the seal. There are notches in the seal to locate it but it appears it has still been rotating around those notches anyway. If you look closely at the inside surface of the outer case of the seal ( the third photo) you can see the wear marks.
The seal case also seems to have distorted. That is a worry as it seems to have been devconned in. It looks like the Devcon has expanded and distorted the seal case.
Does this sound feasible? If the seal has been rotating, then it has been slowly leaking coolant into the gearbox through the back of the seal! As the coolant leaked into the gearbox, the level dropped and stopped circulating, causing overheating and the inevitable boil over and the steam!
As you can see, it is a home made gasket, could the inner overlap be causing or contributing to the starvation or cavitation you guys were speaking of?
Here are some photos. I know the cover is not in the best shape but they are like hens teeth and this is the best I have.
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump7_zpse0ce631f.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump8_zps397e43f1.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump6_zps67ee84b9.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump5_zpsc649c565.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump4_zpsc27616c0.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump3_zps8b327b81.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump2_zps4594e225.jpg)
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Some times its just a small thing thats over looked.
If I am stuck with something, that I cant figue out I sleep on it ;D
most of the time I wake up in the middle of the night and have the answer ;D keep going ken, it will all come togther
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What I would be interested in is if the Impeller is actually the correct one Ken?
If it is too small in diameter (even by 1 mm) then it would not complete the loop of flow back to the radiators, and subsequently steam up. :P
It does look to have an ugly and irregular gap around the circumference. This coupled with that inner seal looking tweaked up isn't good.
I think I have an 85 RF impeller here somewhere. If I find it you could try it ? :)
In my view - adding the seperator will only increase the gap around the bevelled edge of the impeller and the outer housing which will decrease the pumps effectiveness.
LOL Mick - I think Ken has forgotten HOW to sleep since Clarence 2012 !! :(
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The outer cover has the same design cast into it as the tin seperator for the RF model so that explains why the RE doesn't have one,Curse Mr Honda & his frigging magnesium sidecovers causing us all this grief :(
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Hey Ken,
Are you saying you had coolant in the gearbox ? If it's in small qtys you would see it in the breather.
Cheers
Stewart
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Smed, I definitely don't have that plate you speak of in either of the covers I have, #5 in the parts diagram and I don't seem to have #22 in either of the cases I have, the oil seal on the bearing between the pump and the gearbox.
crs-and-rms, The cover is good as you can see and as I have 2 cases I have been able to compare both covers which seem identical so I am fairly sure it isn't damaged or altered. I was using Widerosa head gaskets but the last 2 have been OEM. That is the hardest part of this, blowing a $50-60 head gasket each time I go out!
Hardo, it could easily be the wrong impeller. A past owner of this bike had no idea what he was doing.
Stewart, I did drain the oil a couple of times to check whether I could see coolant but there were no signs of it I could see. I guess if coolant has been leaking into the oil the churning of the gear box has mixed it in too well for me to see it. I will check the breather tube though, I hadn't thought of that.
Mick as far as I know I think Peter is correct, this model doesn't run a thermostat. In the early days the first few times I pulled the motor down and reassembled it I followed a diagram and there was not one on it.
and after sleeping on it Mick, now that I have found this latest issue and thought back on the history, the other cover was leaking coolant out of the pump cover because the case was cracked due to a past owner over tightening the screws. I knew the cover was leaking so I kept topping it up between rides and was able to finish races. It has been since I fitted this replacement cover I haven't been able to finish races. My assumption was that as the steaming happened with both covers the problem must have been elsewhere. Perhaps that assumption was wrong and the source of all this mess was the loss of fluid in each of the covers and this one is leaking more than the first one.
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If water-based coolant is mixed into the oil, it makes the oil milky or caramel coloured. There's no way you could lose enough coolant to cause overheating, without seeing the colour change in the gearbox oil.
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If water-based coolant is mixed into the oil, it makes the oil milky or caramel coloured. There's no way you could lose enough coolant to cause overheating, without seeing the colour change in the gearbox oil.
Thanks Nathan, the coolant I am using, a Toyota one is red, the gearbox oil I am using is Belray, it is red as well. It seems many forces have been working against me.
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Then use water as coolant & see if it go's pink :D :D :D
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I don't own anything new enough to use the red coolant, however...
If the gearbox is swallowing enough coolant to cause the motor to overheat, then surely you'd notice the extra volume in the gearbox?
More importantly, if the coolant-into-gearbox leak is bad enough to require topping up between motos, then surely the pressure in the cooling system would bleed off through the gearbox & gearbox breather, rather than becoming a steam train?
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In automotive applications coolant entry into the crankcase would cause emulsification if severe enough, however if qty was not great & oil temp was sufficent the coolant would be steamed out of the oil and was visible as milkshake in the breather.
Was there any evidence of coolant in your exhaust ?
Cheers
Stewart
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Top marks for perseverance Ken.
Its difficult to help without being hands on, but great to see so many wanting to pitching in anyhow. Troy turned up, just as you posted last night. He is CR mad with five CRs from 85 to 89.
one reason for requesting pics was;
*I thought Smed had it for a moment, but indeed CR and RMs is right, the 84 has the type of pump cover that doesn't use separator plate and you have the correct type to be used without a plate Ken(there is a major difference, between the two).
The separator plate is named in reference to its main intended purpose, that is, to separate the flow of the inlet channel to the pump impeller from that of the outlet flow channel. In the 84's case the flow channels are separated by a division "cast into" the pump cover. That division separates the two flows from instantly recirculating in the pump.
*Troy has also clued me that there is no thermostat in any of his CRs.
*I think it is safe to assume by now, that
-you have new radiators, with hoses correctly routed?
-you have a top end with gasket correctly positioned and that it contains and isolates combustion gases from the cooling jacket?
-you are not producing excessive heat from a combination of incorrect fuel, timing or a lean fuel/air mix.
If the above is sorted, then it is time to
-verify and prove that cooling system containment pressure meets the figure as stated by Honda at 28.4 PSI test, indeed the cap requirement is not to crack until between 15.6 - 19.9 PSI.
(http://i677.photobucket.com/albums/vv132/mc125mick/ken001_zps9d6d6985.jpg?t=1359516419)
- verify that the cap tests to its rated pressure before it cracks. look at the pressure that this system is required to run at. The main reason for increasing pressure containment of a cooling system way above atmospheric, is to be able to increase the boiling point of the fluid in it. Obviously system pressure is limited and controlled by the rated crack pressure of the cap. If your system is incapable of maintaining that rated 19.9 PSI? It will reach boiling(steam) point premature of prescribed engine running temp. I might add, 19.9 psi is a demanding requirement, no doubt a clear indication of engine running temp spec.
When you have achieved the above,,,,,You need to verify the impeller face clearance is correct in relationship to the pump cover Ken.
It looks as though there is a long history of work around the impeller shaft and gasket thicknesses? etc. All of which can effect the optimum impeller face clearance. Acceptable clearance for many is usually achieved by accident, simply by using only correct genuine parts from from Mr Honda, assembled as per his expoded views.
That clearance is super critical to the performance of open face impeller pumps. Through-out industry I have achieved amazing differences in energy requirements or pump head performances, by simply varying that clearance. It may be as easy to repair as just to fit a shim spacing washer of the required thickness behind the impeller to bring it out closer to the cover face, but you first need to calculate that requirement by taking a measurement of the existing clearance.
The impeller face is machined to a tapered profile, as is the mating shear surface in the pump cover. The easiest way to take a measurement is, "crush test" it. It may simply be the case that a thicker gasket material has been used, or impeller shaft set-up has opened the clearance.
I would aim at 0.008" assembled clearance. Don't forget to take into account any measurable impeller shaft end float. I imagine there wouldn't be much, but it would be prudent to check.
pS; I am pretty sure I can help with all/most of your gasket needs. I am off for a day or two now, when I return I will look for a box half full of opened CR gasket sets. It has heaps water-cooled CR head gaskets in it(unlabelled though). I will send you my address. Slip one of those old head gaskets into a freezer bag, then envelope and post it to me as a sample please.
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It may be Worthy to keep in mind, that during my career, every radiator cap I have tested from a failed overheated system has not passed a rated crack test.
Some systems have had other causes of failure, But I reckon the super hot steam blow-off through the cap destroys the spring tension that controls crack point. thereby relegating the cap to the bin.
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Restrictions in head gaskets actualy increase the speed of the water flow, not reduce it, like putting your finger over the end of a hose. I would doubt a jetting/igintion timing issue as it would have seized ages ago, and that is easy to check.
I would be installing a cheap kart inline temp gauge go to the dyno and wring it's neck and find out what temp this occurs at. More than likely you will see a increase in water temp before a rapid drop. The rapid drop indicates steam in the coolant, I would be testing the temp out of the head to begin with.
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Restrictions in head gaskets actualy increase the speed of the water flow, not reduce it.
Speed and Flow rates are two entirely different calculus factors.
The desired coolant flow rate (volume/time) per engine RPM through the heat exchanger(radiator) is the manufactures main design parameter and target in a system not fitted with a thermostat.
A desired flow rate which has a direct correlation to engine and pump RPM.
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Hi Guys,
i have been reading this thread for a while now but have stayed out of it. There have been a lot of good replies which should have nailed it by now, my 2 cents worth is from a very similar problem that i had with my Saloon car i was racing back in 2005/2006.
My main problem was trying to keep the engine at 90 deg c during all race conditions because as you know the hotter the engine gets the more power drops off, this i didn`t need as it was a controlled engine combo and you needed all the power you could get. A lot of hours were spent on the dyno and i started with a temperature probe in the bottom radiator hose and also another in the top hose, this immediately showed me 2 very different water temps and pointed me straight to the water pump having an issue.
A brand new water pump was purchased with a cast iron impeller not the pressed steel type, every second blade was removed and any casting marks and high spots were blended to give a smoother finish but not a polished finish. Took the car back to the dyno and ran it up 3 to 4 times with the probes in to get the temp readings again which were still a lot different to each other, left the car set up on the rollers and changed the water pump on the spot. Bled the coolant system as per normal and then ran the car until it was back at 90 deg c operating temperature, then gave the car 3 to 4 hard runs and each time i had 90 deg c coming out of top and bottom hoses.
The problem was always the water pump not pushing solid water thru the whole cooling system, at higher revs it would not push solid water and this would leave steam pockets in the corners of the heads and create the boiling problems and inconsistent water temps. I believe this is what is happening to your Honda and i wouldn`t go past spending a lot of time in getting your impellor and housing back to what it was when new and then looking to see if you can improve it even further than new.
Just because you can see the coolant circulating thru the radiators on idle may not mean it is pushing solid water at higher revs. Good luck with it i`m sure you will nut it out. Regards Peter.
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Hi Guys,
Mick, all checks out,
-you have new radiators, with hoses correctly routed?
Yes and replaced.
-you have a top end with gasket correctly positioned and that it contains and isolates combustion gases from the cooling jacket?
Yes, all 5 or 6 of them were positioned correctly. They have to be as it is a 7 stud pattern and will only go on one way.
-you are not producing excessive heat from a combination of incorrect fuel, timing or a lean fuel/air mix.
Its running rich at the moment. It hasn't run long enough to give me time to jet it.
I have used 4 different radiator caps. The original Honda one, an 85 250 one I borrowed from Hardo, a 1.4 new replacement and a 1.1 new one which came with the new radiators. It happened on all 4.
Mick, I'll do the squish test as you say next time I'm working on it. Not sure how I am going to find out what the clearance should be but I'll cross that bridge when I come to it.
Thanks Peter, when I put the clear tubes on it in place of the hoses leading from the top of the radiators to the head, it confirmed good flow both sides but there was definitely small air bubbles through the coolant as well.
I think Lozza is right. It might be time to book some time on the dyno where I can observe what happens and narrow it down systematically. I don't want to go through another race season like the last.
If it gets to that is there a place in Sydney anyone would recommend?
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I hope you get it sorted ken ;) This has tested every bodys throughts, and its the most talked about CR250 eva 8)
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Not sure where you live in SYD Ken but RB Racing have a dyno at Taren Point it's only about 3km from Greg Ball Engineering. Not sure if you can run a rear knobby tire on the rig though, he mainly does road & race bikes.
The owner there is also into kart racing and is very knowlegeable, it would be worth giving him a call anyhow.
http://www.rbimports.com.au/
Peter
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after seeing the clutch cover part of the water pump im sure that is the problem the repair is quite poor and has none of the shape that it should have the clearance between impelar and cover would be all wrong i will try and get a pic of my nos cover and post so you can see the differance
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One last and most obvious thing I forgot to mention.
Make sure there are no Kawasaki's caught in your radiator cooling fins.
Cheers
Stewart
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Hi Guys,
i have been reading this thread for a while now but have stayed out of it. There have been a lot of good replies which should have nailed it by now, my 2 cents worth is from a very similar problem that i had with my Saloon car i was racing back in 2005/2006.
My main problem was trying to keep the engine at 90 deg c during all race conditions because as you know the hotter the engine gets the more power drops off, this i didn`t need as it was a controlled engine combo and you needed all the power you could get. A lot of hours were spent on the dyno and i started with a temperature probe in the bottom radiator hose and also another in the top hose, this immediately showed me 2 very different water temps and pointed me straight to the water pump having an issue.
A brand new water pump was purchased with a cast iron impeller not the pressed steel type, every second blade was removed and any casting marks and high spots were blended to give a smoother finish but not a polished finish. Took the car back to the dyno and ran it up 3 to 4 times with the probes in to get the temp readings again which were still a lot different to each other, left the car set up on the rollers and changed the water pump on the spot. Bled the coolant system as per normal and then ran the car until it was back at 90 deg c operating temperature, then gave the car 3 to 4 hard runs and each time i had 90 deg c coming out of top and bottom hoses.
The problem was always the water pump not pushing solid water thru the whole cooling system, at higher revs it would not push solid water and this would leave steam pockets in the corners of the heads and create the boiling problems and inconsistent water temps. I believe this is what is happening to your Honda and i wouldn`t go past spending a lot of time in getting your impellor and housing back to what it was when new and then looking to see if you can improve it even further than new.
Just because you can see the coolant circulating thru the radiators on idle may not mean it is pushing solid water at higher revs. Good luck with it i`m sure you will nut it out. Regards Peter.
Off topic
Stewart Peter :-[I am not following this are you saying the inlet and outlet of your radiator were the same temperature :o Wouldn't you want a temperature drop across your radiator ie the radiator is getting rid of heat ot of the coolant? I wouls have thought that coolant temperature would be high when exiting the engine would cool as it passes through the radiator and then returned to the engine ready to absorb heat again. Basically a cooling system is a heat pump. I am not trying to be a Smart ar.. or an I miss reading your post
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Hey Scrivo,
Not my post but I also agree with your question, I would expect coolant leaving the radiator to cool the engine would be colder than coolant exiting the engine after it has cooled the engine.
Peter (Billet YZ) can you enlighten a couple of inquisitive old bar studs.
Cheers
Stewart
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How much is the radiator going to disperse heat if there is no wind rushing through it while it sits on the dyno? I can't imagine a lot. Not trying to be a smart a... either but I legitimately can't imagine it doing much to cool it off without the air flow through the fins.
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How much is the radiator going to disperse heat if there is no wind rushing through it while it sits on the dyno? I can't imagine a lot. Not trying to be a smart a... either but I legitimately can't imagine it doing much to cool it off without the air flow through the fins.
Pretty sure they set up big fans blowing air at the radiators.
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All the rolling road dyno's I,ve been involved with have had the fans, as Peter says.
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How much is the radiator going to disperse heat if there is no wind rushing through it while it sits on the dyno? I can't imagine a lot. Not trying to be a smart a... either but I legitimately can't imagine it doing much to cool it off without the air flow through the fins.
Pretty sure they set up big fans blowing air at the radiators.
That would make sense then. Perhaps Peter had the fans turned off for his test
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There would still be a significant variation between top & bottom (unless he's running a crossflow radiator not common). What you find with out fans is that the temp would continuously increase, the rate would generally be dependent of the load applied.
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Sorry for the slow reply guys just got home from work.
The dyno i was using did have the normal large fan as without this you would have overheating problems very quickly, the aim was always to have consistent temps out of both hoses. With the race car if you had cold water coming out of the top hose this pointed to the water staying in the radiator for too long and the fan doing too much of a good job, this then points to the water not being pumped thru the system consistently.
In my case this proved the water pump was creating air and not pumping solid water thru the system, once the new water pump was fitted my method of achieving the desired water temp of 90 deg c was a disc that i replaced the thermostat with and it had a 13 mm hole in the middle. If this hole was to big the flow would have been faster and the coolant may not have had enough time in the radiator to cool, if the hole was to small the coolant would have stayed in the engine for to long and got to a higher temp and again this would introduce different temps from the top and bottom hoses.
In the end the water temp maintained 90 deg c and the retarders on the dyno had the problem of overheating and needing a rest, this is a problem we never had before the water pump was sorted. I believe the fans for most dyno`s simulate approx. 100 kmh of road speed.
My main point is that you need to have solid water pumping thru the whole system and pushing out any steam pockets that may be in corners of the coolant passages before you start to worry about achieving the correct running temps. With no provision for a thermostat in the bikes you would need to look at a few other methods of controlling water flow thru the system. Peter.
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just found the nos clutch cover and taken the pics just have to work out how to post them in here
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sorry could not up load the pics
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sorry could not up load the pics
Mate, if you want to email them to me I'll put them up for others reading this post, after I drool all over them first though :'(
Ken
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pm me your email and i will send them to you
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you can see his email link under his avatar
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pics sent
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(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/84CRClutchCover2_zps282babb1.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump7_zpse0ce631f.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump3_zps8b327b81.jpg)
It's amazing this thing runs at all!
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(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump6_zps67ee84b9.jpg)
Ken - I just had a thought....
It actually appears that the hollowed out part of this has actually been filled with metal-set or some sort of epoxy...... I realised this looking at the new cover.
I would think that maybe this would actually restrict the flow a GREAT deal ... ???
It would also rely quite heavily on the small gap between the inlet pipe on the top (from radiators) and the pump cavity.
Maybe, just maybe the pressure from the pump is actually back-flowing UP and into the supply (from radiators) line????
Buy that cover - and all will be good..... surely ! :-\
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Thanks Hardo,
It is understandably not for sale, but...I am going to get the Dremel set out and practice some sculpting. You asked if it was the correct impeller. I don't know but this one is for sale on eBay listed as a genuine part. It appears to be similar but the blades seem longer and it has the nut. On the parts diagram there are 2 listed. One seems to have the nut, the other doesn't. If you can't find yours, I am hoping someone on this forum with this model can confirm what the correct impeller for this model should look like.
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/impeller_zps44bc5d30.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/Waterpump5_zpsc649c565.jpg)
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the part number for the re is 19215-ka3-710 i would remove all that old repair have it blasted to remove all the rot the use quick steel to repair it its more like puty and much better to shape than devcon or jb weld then shape it when it s nice and hard .thats how i repaired mine i know its easy for me as i have the new one to guide me . i then remove the coolant and impelar cover after each ride ,bit of a pain but havent had to re do mine for three years
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Is this a cover
http://www.hondascooterspares.co.uk/spares/epc2.asp?ModelID=12025&pageID=EAA030&m=HONDA+CR250RE%2DK+CRANKCASE+COVER+84+86&uID=0
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If it is, I'd be buying it..... :D
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300 pounds....WTF
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Looks like this bloke may have a similar problem........
http://www.dirtbikeworld.net/forum/showthread.php?p=1552833
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or this
http://www.ebay.com.au/itm/HONDA-85-ATC250R-250R-CLUTCH-COVER-11340-HA2-000-19215-KA3-710-19241-HA2-000-/281031704143
Is this the corrcet part number
11340ka4740
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this is the part number11340-ka4-740
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I don't know how many times it has been said on here that the CR250RE 1984 water pump cover was a "ONE OF"!!!!!
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Looks like this bloke may have a similar problem........
http://www.dirtbikeworld.net/forum/showthread.php?p=1552833
I think we know this bloke ;)
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Sitting there contemplating this bike, and a logical sequence of steps to take, it occurred to me that I have never have really understood for sure how the ATAC mechanism worked in this bike and why it is linked to the inside of the waterpump. I assumed it had something to do with the centrifugal force created by the spinning of the pump activated the shutter in the exhaust port but I haven't really given it much thought beyond that. You could say I had other things with this bike on my mind. To assess this issue properly though, I think I need to know exactly how the whole ATAC mechanism is supposed to work and what the pump actually does in relation to it. I noticed that one piece has a rectangular key on it which is off center and locates to a part coming down from the exhaust port and that piece could easily be put in back to front, possibly changing the behavior of the whole mechanism. Can someone shed some light on what drives what and how this part of the bike works?
Thanks in advance for any assistance.
Ken
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/REInside3_zps2bbe4fcf.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/REInside2_zps3451451e.jpg)
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/REInside1_zps73e9f975.jpg)
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i will take those measurements for you tomorrow night
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Ken, You are correct in the way the ATAC system works but it has no bearing on the water pump, they used it as it was a drive point thats all.
It will have no effect on the running of the pump.
I thought we had spoke about this some time ago re the issue you are having with your 250 and we had the same with one of ours. We replaced the head (after having it faced and still had the same problem of overheating) and now have not had the same problem again.
I assumed it was a slight crack in the head that I could not pick up by eye.
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Hi Shane, yes I found some literature on it today. When working correctly, at about 6000 rpm, the mechanism on the inside moves out and activates the closing of the ATAC valve in the exhaust port.
We did talk. I have tried 2 heads on it and it did it with both. You don't have any spare right hand side clutch covers kicking around you want to sell do you. It wouldn't have to be too good to be better than what I have.
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You don't have any spare right hand side clutch covers kicking around you want to sell do you. It wouldn't have to be too good to be better than what I have.
Kenneth, are you sure mate???
Look at this one....
http://www.ebay.com/itm/1984-Honda-CR250-CR250R-Dirt-Bike-Engine-Clutch-Cover-repaired-/121062085071?pt=Motorcycles_Parts_Accessories&hash=item1c2fdcd1cf&vxp=mtr (http://www.ebay.com/itm/1984-Honda-CR250-CR250R-Dirt-Bike-Engine-Clutch-Cover-repaired-/121062085071?pt=Motorcycles_Parts_Accessories&hash=item1c2fdcd1cf&vxp=mtr)
:)
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hi ken have done the mesurements will send tomorrow for you
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wow 7 pages on how to modify a 1984 cr250
thats a lot of mods ;D
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wow 7 pages on how to modify a 1984 cr250
thats a lot of mods ;D
Seven pages and we haven't even got past the waterpump yet ... wait until we get into porting, pipe and carby setup ;D
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email sent ken hope it came out ok let me know
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No need to mod them Rusty you know they are like lighting the way they are!
Ken, Most of the cases I have are worst than yours so I still don't think that is the problem.
If the water impeller moves (rotates) when you turn over the engine then that would pretty much rule it out. They are a simple system.
We have not had to much trouble with the 3 bikes we have (outside of the bike I ride now that had the head problem), if they is no blockage in the lines and you are bleeding it correct (had no issue with this ourselves) than I am at a loss. When you fire it up and remove the cap, the water flow should increase as you free rev it, that would mean it is getting good flow and rules out most things.
Outside of that it can only be head / barrel / cap.
Shane
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I’m with STW, I reckon you may have a crack in the head / barrel
I know you swapped the head for another but they could both be duds, stranger things have happened.
Cracks can be hard to see with the eye because they sometimes only open up with heat.
There are too many pages to look back through on this but I thought you said you had checked the water flow? With some clear hoses or something.
The recess in the pump case that is filled in is pretty minor as the outer cover still should have a good open area.
Have you had the motor running at your workshop with the cap off?
As well as watching for flow if the water settles down you can look for bubbles in the water, If there are any bubbles then they could be from combustion gases.
I think there is some testing gear that can check for gases, I think someone already mentioned it
You should talk to some car engine reconditioners about getting the head crack tested, they would deal with this quite a bit whereas motorcycle mechanics would deal with it rarely.
I reckon you need to get it tested properly just so you can at least rule it out.
Compare the cost of getting it tested to the cost of buying more head gaskets.
You can even buy crack testing spray cans from industrial type hardware stores.
I use it on odd jobs.
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listen to shane he knows his honda stuff ;)
geoff you should make some you could retire in 2 years ;D
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Was at TM Bills event in Taupo yesterday and got talking to a rider that has said 84 cr250 and has been having exactly the same problem, has had spent lots of money on head gaskets and had numerous mechanics look at the bike but no one has been able to sort it out.He had almost given up and purchased an 85 cr250 to take its place.He had 1 more gasket left so fitted it and left the bolt out that secures top of motor to frame.Rode bike all day and no problems.he seems to think that the frame flex has been the issue all along.Just a thought and may be worrth a try
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Thanks guys for all your comments. I have a new barrel but it requires a rebore and a new top end...$400, when I have only recently spent that on the current barrel. The course of action I have decided to take is rule out the cheap fixes first. The mechanical seal was suspect so I have rebuilt that whole system with all new seals. If it was slowly leaking coolant into the clutch cover it won't now. I have also changed coolant to a blue motorcycle coolant so I rule out the coolant and see a colour change in the oil if it does leak into the gear box, replaced all the tired head studs with brand new Honda studs and after Cooch's very interesting comment, I might go half way and put some teflon washers on each end of the head brace. Don't like the idea of racing a 30 year old motocross frame without all its bracing!
Thanks to Hardo and Nathan for the blasting.
Thanks Alex for the diagram, I followed all your measurements with my Dremel. The case looks better in the flesh than it does in the photo.
Fingers crossed!
(http://i1213.photobucket.com/albums/cc468/24HourMerchMan/7e68e3c8-8808-4623-bbe1-8b951e7ebe09_zpsda45bf27.jpg)
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There are plenty of head stays left off old bikes because of the issues they cause to heads and cylinders with frame flex, it's an idea worth serious consideration.
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looks great glad to help
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Thanks guys for all your comments. I have a new barrel but it requires a rebore and a new top end...$400, when I have only recently spent that on the current barrel. The course of action I have decided to take is rule out the cheap fixes first. The mechanical seal was suspect so I have rebuilt that whole system with all new seals. If it was slowly leaking coolant into the clutch cover it won't now. I have also changed coolant to a blue motorcycle coolant so I rule out the coolant and see a colour change in the oil if it does leak into the gear box, replaced all the tired head studs with brand new Honda studs and after Cooch's very interesting comment, I might go half way and put some teflon washers on each end of the head brace. Don't like the idea of racing a 30 year old motocross frame without all its bracing!
You’re attacking a few issues but it sounds like you haven’t actually confirmed what the problem is yet?
Spending $400 on a barrel doesn’t sound like a cheap fix to me.
Unless the barrel has a crack in the liner then I doubt the barrel is the culprit.
If the mechanical seal was the problem then you would have enough water in the gearbox oil for it to be obvious.
Didn’t you run some clear hoses from the pump to watch water flow?
I doubt the shape of the impellor area was causing enough cavitation for it to overheat (although according to my wife I have been wrong before)
If the head stay is causing the head gasket to break seal or the bolts are pulling through the barrel then the head gasket should have shown signs of leaking. The leak will be from the combustion chamber to the water jacket.
Like wise if the head or barrel was warped.
Did any of the gaskets show any signs of this?
I have heard of head stays breaking heads before, the holes in the brace should be slotted to allow for some ‘give’ so it can cope with frame flex.
My money is still on a cracked head, both the heads.
It bothers me that this is still giving you grief, if you want to post down the old barrel, head and an old head gasket I will have a look at them for you. If I can’t find any cracks in them I will wear the return postage cost.
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Thanks Geoff,
Your offer is much appreciated and I might take you up on it.
The head gaskets did let go and there were marks on the head gasket where the combustion gases had leaked through to the cooling jacket. My assessment is that this happened after the head was warped though. I believe there is a good chance that originally the engine overheated because the coolant level dropped to below the point where it would continue to circulate. I want to get the basics right first. Make sure I have a cooling system which is circulating properly and not leaking and then go from there.
I finished putting it together today and started it up and ran it for a while with no incident. I have a race meet this weekend where it will get a work out and see what the score is. The brace is not slotted so I think I am going to put the next size down in bolt diameter into the head stay where it bolts to the head just to give it the 'give' you speak of.
Regards,
Kenneth
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So how did it go is the problem solved????
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Yes, no steam for the train!
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Sweet! All done!
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So how did it go is the problem solved????
Cooch, I kept thinking I should have put something up on here letting you know but I still can't believe it myself and I didn't want to tempt fate. Practice and 3 races and absolutely nothing! The bike performed like a train!
I took the head brace off at the track. Thanks for the tip. One day I might put it back on and see what happens but for now I am going to ride the wheels off it and make up for lost time. ;D
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That's freakin awesum to hear isn't it great when a plan comes together ;D ;D ;D ;D
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glad to hear its all sorted.
so what was the root cause then?
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Great work,this is a prime example of the positive nature of this forum.
PS cooch good to see you at Easter I look forward to coming over and catching up with you at a Viper round.
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glad to hear its all sorted.
so what was the root cause then?
Hoony,
I believe it was either a faulty mechanical seal allowing the coolant to slowly drain into the gear box to a level where it had stopped circulating and the engine was then overheating or the frame flex was causing the head stay to distort the head, thus blowing the head gasket.
Thanks again to everyone for all your suggestions. We got there!!
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nice work Kenneth CU @ the nats
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Thanks ken. i admire your persistence. well done.
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good news enjoy
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Was an awesome event Craig , Bill and co are very passionate about VMX.Got to get the 500 sorted and get out there.It was Rob Sutherland who told me about his 84 250 with the same problem. Spent the evening with him, Captain and Fossil.Rob has got a very interesting background in MX finishing 3rd in the British Championship in the early 80s. :o :o
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My money is still on a cracked head, both the heads.
Luckily I didn’t bet the farm. :D ;D
Re; the head brace, keep in mind that it is not supposed to strengthen the frame but to merely stop vibrations.
So if it was the headstay causing the problem then you might want to give the frame a good inspection as it may be flexing more than normal.
Glad you got it sorted, all other problems will now seem insignificant.
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Cheers
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I thought I'd let you guys know, I have now taken this bike out 4 times and really given it a workover with no issues so far. YooHoo
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Yehaa a !!!
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Great that one more bike that I will be behind, what will i do between races now!
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thats great news enjoy
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This corrosion problem on this model seems to be on most bikes.
One question do you think there would be a market for a billet replacement cover??
What price do you think it would fetch ???
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Paul, Shane tells me your bike has been sorted and is not an issue
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Paul, Shane tells me your bike has been sorted and is not an issue
All good Ted
I was thinking I could do a run of billet covers.
(I sell cnc machines for work )
Should get the bike next week :)
See you in Canberra
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if you can do it i would be interested a 1985 CR500 one. i reckon there would be about 4 forum members in the same boat.