OzVMX Forum
Marque Remarks => Suzuki => Topic started by: oldfart on October 30, 2007, 08:32:18 am
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Six months in the building and still going :)
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RHS
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Looking really good Stew! ;) I meant to reply the other day when I got the pics in the mail 8) jealous of those wheels particularly! :P
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Did you start it on the weekend mate? Im sure i felt the earth move. ;D
She has Connondale written all over her and is gonna thump.
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OK so it doesn't say Yamaha on the tank but it's a fourstroke, a 500, a single and I love it!
I rode one in NZ and was very impressed
Brent
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Nice work.
Inspired by the VMX article???
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The photos don't really do her justice Oldfart. She looks better in the flesh 8) Certainly a credit to you.
Looking forward to a video of her in action.
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Oldfart
I have finally seen a thumper I really like. Probably because it is very much like mine!! I'm keen to see what sort of exhaust you end up with.
Mine is a little bit different to yours as the frame is made from joining the rear section from an RM250C1 to the engine frame section of an SP370. The geometry looks very much like yours which I'm guessing is a DR400 frame with an RM swingarm.
I'm using the RM250C1 forks, (aluminium) fuel tank and steel swingarm and some Marzocchi piggyback shocks. The SP370 motor was big bored to take a DR400 piston and has a 36mm Dell Orto pumper and a custom exhaust. Standard compression, valves and cam timing. I'm using the RM rear wheel and can't decide if the RM or SP front wheel is the best.
I built it in 1979 from a brand new SP370 and an RM with a blown motor. It was my enduro weapon for many years and then I used it for fitness training on an MX track in the mid 1990s (it's great for working up a sweat). It now patiently waits in the shed and gets ridden about twice a year.
David Lahey
Gladstone
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looks great im not a fourstroke fan but id have that in my shed any day
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This weekend should see the rear brake Assembly finished along with the front brake cable .Undecided to which throttle type Um mm fiesta over it for another week .
OK the frame is definitely a DR 400 ( 1980 ) vintage Tony recognize the old girl
Front forks from a Rm 250 N (38 mm ) internal springs Honda 2 piece with Yss Pd valves
Rear shocks are DR 500 -1981 ex USA Ebay Item \
Swing arm RM 250 -400 RM c2
Seat Rm 125 b and the same for the tank which was acquired thru Ebay USA for a song $10 plus $20 shipping ( 8 weeks ) . The minor Dents where removed a per posting.......
To make the tank fit the frame new mounts had to be fabricated at the front and welded on - The rear was easy as the section that was removed to fix the dents in the tank was hand fabricated to suit
Tip ... I used plaster cement to take a mould of the rear of frame - which became the plug - filled it up with molten lead ...then that became the jig to fabricate the infill section of the tank .
All the unnecessary brackets where removed , new ones added for side covers - CDI relocated - coil relocated - extra gussets welded up at steering head and all welds re done and cleaned up
Frame was sand blasted then acid dipped - one coat of base coat - 2 coats of 2 pack black
The motor was Stripped bead blasted and had a total rebuild - head rebuilt -ports worked and flow tested with good results :) motor was 2 packed and assembled
Hmmmm ... used a piece of armour flex ( black a/c lagging ) to get the clearance plus shape of exhaust ( exits to the right and over the clutch cover -under the air box -rise to clear wheel and exit LHS to match side cover
First attempt at making one at me mates exhaust shop looked shit house .... so may have to bite the bullet and get one custom made ( $400 ) ouch
Tank colour will be Rm yellow with black SUZUKI stickers cleared over
Waiting patiently is a DR 500 ( 2008 resto )
PST typing is not one of my choosen skills ;D wheres the kids when you need em lol
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Well that was one hell of an explanation Bro,The bike looks good.Pity about the tank though,oh and the kids how can they help, you are always hogging the computer anyway.
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Here she is all finished in time to take to CD5
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Whats she ride like Stewy? Have the neighbors complained about the boom boom boom? ;D
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Pokey ....awesome power in all gears, still sorting out the front end as there is no in between ( either too hard with XR springs or TOO soft with RM springs ) looking for softer up spring as per BRENTs reply in another post .
As for the noise factor I reckon its a tad above the legal limit ;)
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Jeez Stew, she looks the good mate. Nice job! 8)
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Hi Stew,
First up, I ride a Yamaha but I like the looks of this!!!!!!!!!!!!!!!!!!!!!
(I do own a Suzuki as well)
I added a top out spring from a set of 38mm forks on top of the two XR springs. This will reduce the spring rate from about 25lbs to 23. Mine is really smooth at this setting. Try about 5mm preload on the springs, by the way what do you weigh?
Most Yamaha’s and Suzuki’s of that era have kayabas with interchangeable internals so you have a few choices.
I’ve got a set of PD valves in my 43mm forks on the other bike but have not tried them yet. I’m hoping to get the forks onto my race bike in the near future. I’m keen to see how they compare with the Race-Tech emulators.
Don’t be afraid to play with the PD valves. If you find the front is harsh, back off the PD valve preload and try again. Make your self a long hook to fish them out.
Hope this helps
Brent
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very nicely done, there is some hours behind that project i bet.
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looks like a double strawberry icecream. You know you shouldnt but damn its just sooo nice you have to have a lick.
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another suzuki for cd5 well done looks cool 8)
what size header pipe did you use ???
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First bend out of the head is 38mm OD, then steps up to 44mm OD all the way to muffler
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nice. the gold forks are somthing ive never seen before. the only thing i can say i dont like is the tank. to me it doesnt suit the rest of the era of the bike and looks too old for the rest of the bike, but as long as your happy with it thats all that matters.
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stu you old fart looks similar
baz
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Bring it out to a meet some time and we will put them side by side to compare ;D
Looking good all the same.
Just need to sort out the front springs ( Brent J gave me the heads up at Conondale ) so will have a play and see it it works out .
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OLD FART IM PISSED I CANT FIND THE SPRING INFO I PUT IN THEY ARE 110% GROUSE.WILL BE AT C/D IN 2009 SO MUST HAVE A BREWSKY WILL HAVE ONE FOR YOU AT THE MERMAID BAR AT KLUB KEVLAR AGM.BACK TO THE MUSTANG NEARLY DONE
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Dr 400 Mk 11 almost complete
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wow what frame is that in rm/pe400 beasty looking fourstroke too should go good :)
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frosty , It's a Dr 400 frame with a Rm rear cut added, motor is SP 370 with Dr 400 top end
Decals are 1980 rm .
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its a good job hoping to do my gt80 up before march its going to be like brand new i hope ;D
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what shocks?
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those Dr 500 USA jobs with piggy backs ...Rebuilt by RAD . Not too many bikes sold with them in OZ and THEY WHERE reasonably cheap to buy 6 months ago
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i couldnt see the reservoirs
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They are hidden behind side covers
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if you want more of those shocks ask Geoff Udy in QLD. he now runs a yamaha shop but back when he was a suzuki dealer and racing DR 400/500's he may of removed those and fitted DeCarbons. he was one of the few dealers that got a couple of those US market 250/400/500 DR's
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Looks really good. Have you sourced fork springs yet?
I've got a set coming, originallyfor Maico 38s, but they are the hardest set [49 I think] so they may well be too stiff, the only ones I could find, about 22.5".
I've got an Acerbis 20 litre tank so the springs may work with that
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Wash that mouth of yours out Walter. '' loose lips sink ships "
Next weeks task is to sort out springs on Mk 1 ...Bazza keeps telling me has Maico springs, but for the life of me he can't remember what model they came from .
So I'll start from scratch and do the process of elimination thingy, this time I will put to paper and write it down ::)
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Sorry , it just slipped :D I will delete the post tomorrow ;D
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I asked Wulfsport, but the only springs they had were for the 40mm [I think] 81 forks. They thought these were too tight a fit in the 38s and would bind. 38mm forks are bit difficult for springs as they weren't in manufacturers' model ranges for long. All the standard suzie springs are too soft and XR 250 springs aren't available in the UK. Race Tech do springs on demand and have a really good clear website, so last resort would be to buy a set from them
Progressive used to have stuff listed but their site is poor and I haven't managed to access their fork spring info for a while, not sure if it's still there.
As for the RM swingarm, what's the main advantage, weight, travel or handling?
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Thats alot of running around , when we have three big shelves just for Fork springs ???
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Allows bike to be in proportion with front, evenly balanced. Standard Dr shock mounts are 395mm from swingarm pivot where as Rmc are 340mm with an overall increase in rear wheel travel.
Handling is an issue AS THE FRONT needs sorting, having said that she has great corner speed due to engine brake speed ( hardly use brakes at all )
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i think the spring info is still on progressives site. if not im sure i have it. i know its hard to find springs for some 36mm forks
here its is
http://www.progressivesuspension.com/pdfs/7100-105.pdf
too easy
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If we get the orders we make them , but it seems so many just are just constantly talking about it . ( its not feasable to produce springs for gunnas ;) ).
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yeah but you only do orders of 1000?
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Thats not correct , like i said to you before many times , if it is a going model and the support is there , we construct and make a run of 100 from Chrome Silicon steeel ( the best available).
I will take 50 and YSS Europe will take 50. Out of the 50 , I like to see at least one constant buyer ( for Example Maico springs 4.5 N ) I am not going to buy 50 springs to sit on 49 and keep one odd request happy.
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OK , I am gunna change it ;)
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well close, one zeros too many.
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By the looks still a 1 and two 0 to many for your needs , and probaly to expensive too . :o Happy websurfing Leith. ;D
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Ok I will bite
Rm 250( 79) 38mm forks are starting point way too light
spring length = 580mm
windings = 59
gauge = 4.22mm
spring OD = 30.45
Id = 20.73
Travel =235mm
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That does not bite
I can offer 29 OD 540 freelenght 4.8N if you just need one
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Thanks 77 I've bookmarked that. Seeing as how KTMs used zzochi 38s as well then one of their springs may work
OF I have 16.5" 4.5" stroke shocks on a standard swingarm at present. It seems to be a slight rising rate 2 to 1 ratio so I have just over 9" of rear suspension.
I can sit on the bike with my feet flat on the ground, and the kickstart is still low enough
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With regard to springs for this, I'd pick the weight to be about the same as my XT500.
Any settings I use, and I'm happy to pass on, were what worked well at that time. I am continually looking for improvements. Oldfart, ask Asasin what he thought of my front suspension, and it's been improved again.
I used XR250 Honda springs, both main and secondary as they were available and free. They work out to be about 25lb/in or about 4.5N, Walter?????????
What sort of price would you be looking at for making the springs you mentioned in your other post? I think you mentioned 4.5N. This seems to work well enough to equip all my 500's
I've tried a third spring (23lb/in) with what turned out to be too much preload but now run just the two XR springs with only 2-3mm of preload. This is just enough to stop them rattling and no more.
THE HEAVIER SPRING WITH LITTLE OR NO PRELOAD GIVES A MUCH SMOOTHER RIDE! the bike sits higher, is far more responsive to bumps and bottoms a lot less.
I recently changed my fork oil from 10wt to 15wt as the bike was bouncing back a bit to much on jumps and what an improvement in overall ride. You don't realise how much of what you feel through the bars is not actually bumps on the ground but the wheel slamming back down too fast.
I like to ride modern bikes to give me something to aim for.
If you want to play with suspension I'd suggest getting seveal bottles of fork oil, different weights, and be prepared to throw it all away trying different settings.
Spend a day removing and adjusting PD valves trying different fork oil heights and weights.
AND, don't be disapointed if a whole day seems to have been wasted and you see no improvements. Remember the experts became experts very, very slowly.
Brent
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Thanks for your input Brent , yes 4.5 N or there abouts should work fine for up to 100 kg rider in combination with the PD valves, Do you think the same spring could also fit the XT ? Would 550mm freelenght be enough ? What max OD can we make them ? What stroke is required ?
If we make a batch , they would sell individually for $179.00 if you or a club buy a few , we can talk.
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Walter & Brent , hang on a minute ... The XR springs I have tried are 4.95m thick . So are there Two guages available in the XR series 4.9mm and 4.5mm as the 4.9 is way too stiff .
Spent the afternoon trying different combos .
1 = Xr250 twin spring 4.9mm too harsh not using all available travel .... possible spring bind
2 = Rm 400 spring ( 540 long) 4.22mm with top out spring ( Brent issue ) ..... smoother ride ... bottoms out
3 = Rm 250 spring ( 580 llong ) 4.22 and top out spring improvement over above ... still too soft
Todays conclusion try same windings as Rm springs ( 59 ) but need heavier wire possible 4.5 mm
Bye the way I have a XT 500 , DR 400 are much lighter ;)
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When dirt bike "white brothered" a DR back in 1980 they ended up with much the same weight as they started due to stuff like the forks weighing more.Around 290lbs fully gassed was about it.
TTs came in at 274.5lbs with a us gallon of gas and a 43.6% bias on the front wheel.
Both the DR engine and frame weigh pretty much the same as TT , stuff like the rear wheel assembly is likely to be heavier than TT/XT
Standard a DR is much better balanced than a TT, 4 years was a long time back then.
Race Tech has a neat chart that gives a ball park figure for fork springs. It seems to correlate with what you and others have incrementally decided upon OF.
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Oldfart
I think my XR main springs are 4.5mm so my apologies there. If I get a chance I’ll pull out my springs and measure the main and secondary springs this weekend.
The RM springs you gave specs for in a previous post have a rate of about 16.4lb/in. You need about 25lb/in.
Race-Tech suggests 25lb/in springs for the front of an XT/TT or racing, Works performance say 23, I tend to agree with Race-Tech.
Try 25lb and if it’s still too stiff I’d be looking at your damping
Check out
http://www.pontiacracing.net/js_coil_spring_rate.htm
and save the calculator. You can then work out what rate springs you have.
Use this
http://www.proshocks.com/calcs/2spgrate.htm
if you use two or more springs
The XR springs I have are just on 25lb/in using both springs. The main spring alone is about 34lb/in and impossible to ride. Adding more springs (coils) reduces the rate. I originally used the top out spring in mine to reduce the 25lb to 23lb as it felt stiff on small bumps but this was caused by using too much preload. When I went up to 25lb and no preload the stiffness went away and it also bottomed less.
My bike weighs in at 126kg (277lb) with a full tank of fuel so I’d guess your DR is pretty close.
My current setup is
PE175 fork legs with IT465 damper rods (to get 9” travel)
25lb/in springs, 2mm preload
15wt oil at about 140mm from the top, not sure here as I measure mine at full extension with springs in place.
Race-Tech cartridge emulators with 64lb/in springs with 2 turns preload for less high speed comp.
I have a set of YSS PD valves and as soon as I get time I will fit them start playing.
This set up is for now, if I find an improvement next time out it will change. I’ve changed the set up twice since Conondale and I expect a few more changes through the year.
The right spring will hold the bike up, sag 6-10% with the weight of the bike and 25-30% when you sit on it. After that it’s all down to damping.
My two cents worth anyway
Brent
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Brent , have you made those jets for the PD Valves ?
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Back to the old question , should we make a universal spring to suit ? What demand is there? Or does somebody already offer that size and rate ?
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There doesn't appear to be anything available in the UK, though I may change my mind after the upcoming show. But seriously how many people are modding stuff?
If you wanted to market them you could get an article in VMX and UKs Classic Dirt bike, that would shift a few sets
Also the UK's yamaha thumper website would be worth a pitch. that site's so good XT fanatics check it from around the globe
Every year a few people do the Heroes Legend Paris Dakar on XT500s. This modern event was set up specifically for XT500s
Their website would be worth a punt.
Lastly Kedo have now got an outlet in USA and this german website is the first port of call for a lot of the Heroes guys, so it would be worth contacting them to see if they'd be interested in shifting a few sets, that is if you aren't already tied into another european distributor
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Thing is old stock springs turn up at under £50 a set in the UK so folks are still going to scrabble around for alternatives.
Brent
If my Maico springs do turn out to be [as expected] too hard for anything other than a desert going petrol bowser; I was thinking of cutting my spare wimpy RM springs down to the length of the spacer and softening the overall spring rate that way. There's a few inches of spacer so I thought that might help, or am I being thick?
My forks are off an 81 Rm 125 and are have over 10" of travel
I've raised the stanchions over an " and the bike is OK above walking speeds. I know I could steepen the head angle more, as when I got it it was running the max rear shock length and standard 7 to 8" forks, and there wasn't a hint of instability.
There's an article by Super Hunky that goes into a lot of detail about cutting and shutting springs, though in the context of stiffening , rather than softening, suspension
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What is the link to that TT site ?
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http://www.yamaha-xt500.com/phpBB/portal.php is the UK site
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Thanks Cloggy
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I finally got my old RM250C/SP370 hybrid out for a ride, motivated by the possibility of riding it at the next Conondale Vinduro. Here is a photo from yesterday and there is a bit o a story in the Vinduro forum
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looks pretty good whats the go with vinduros im looking to ride some Vic vinduros this year do 2 and 4 strokes go together i have heard three bikes go at once or something im hoping to go alright on my pe400 thanks Michael.
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Frosty there is a Vinduro forum in the top part of the Ozvmx forum page and there is info there about the Victorian Vinduros for 2009. The Conondane Vinduro I'm hoping to ride will probably be a poker run ie you just ride at least five laps and get a poker card each lap. Not sure what happens in Victoria.
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heres a couple photos i found
(http://www.vintagefactory.com/CIMG0007.JPG)
(http://www.vintagefactory.com/CIMG0002[1].jpg)
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Hello, I'm new here. It seems like a lot of the posted pictures don't come up??
I have a 78 RM250, and i might be able to get a DR400.
My plan is to combine the two, using only the engine and the part of the frame around the engine from the DR, rest including rear subframe from the RM.
As I can read here a few of you has bikes like this, but I'm only able to find pictures of bikes with plastic tanks and 79 style sidecovers. Is it possible to post some with alu-tank and the small 76-78 sidecovers?
Thanks
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Oldfart has recently done both standard DR and a DRM hybred framed bikes. As he hasn't yet posted as to a front spring source it's possible he hasn't come to any firm conclusions on the relative merits.
I went to the UK twinshock show and sourced a supply of springs. The guy said he had no problem getting Maico 38mm stanchion springs in any weight I wanted. That appears to be 25 lbs per inch/0.45 k per mm
They are the right length for suzy 10" travel fork and fit.
I'd like to know what the spring rate is for the RMC swing arm when attached to the DR frame.
I got a secondhand set of 15.5" Falcons off an RM at the show as well and there was a complete frame and swing arm for an 1978 RMC . The bloke may still have it. They aren't popular here as the cutoff date for twinshocks is later then OZ/USA
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Dr 400 frame with mods visable
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DRM
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This will fit
http://cgi.ebay.com/ebaymotors/1983-Suzuki-DR500-DR-500-Aluminum-Rear-Swing-Arm_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a0Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem110347741658QQitemZ110347741658QQptZMotorcyclesQ5fPartsQ5fAccessories
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The BarronVMX DRM
(http://www.ozvmx.com/images/forum/drm400.jpg)
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today i found an old ariticle froum europe with a whole heap of colour photos of the hagon DR/SP suzuki and the hagon yamaha, and also the cheney framed 2 stroke yamaha. Pitty VMX mag has already done articles on those bikes.
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(http://www.vintagefactory.com/CIMG0007.JPG)
Looks a lot like this one ;D
http://www.trademe.co.nz/Trade-Me-Motors/Motorbikes/Motorbikes/Classic-vintage/auction-200594577.htm
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I'm dubious how the fast bits bike handled. My DR was pretty noodly with 36mm PE forks
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Recently I got a few more bits of historical data.
Dirt Bike used RM frame bits on their 1979 DR370 due to the SP derived frame handling like a " '49 Dodge with three flats and a bent axle".
The 1980 DR400 frame was RM based and they thought really good except in tight slow going, " an excellent slider" "278lbs with a gallon of gas", identical to TT.
They weren't impressed with the suspension, or the weight of the steel swingarm, and didn't like the long brake stay arm. So when they came to modify it they left the frame alone.
By 81 a Motocross Action article on the DR400 bike for the 4 stroke nationals described that the head angle had been steepened 1 degree [from 31 degrees to 30], the motor had been dropped 1" in the frame and the footpegs had been raised by 3/4 of an inch.
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Have scanned various Suzuki DRM370/400 articles from US dirtbike magazines over the years. Happy to post them up if anyone is interested.
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i would be interested to see the motorcross action DR 400 article
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Me too!
Thanks
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And me!
Anything you've got!
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............same here! and thanks for the KDX article !!! ;D ;D ;D
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(http://i574.photobucket.com/albums/ss185/mposs/Save-1.jpg)
(http://i574.photobucket.com/albums/ss185/mposs/Save0001-2.jpg)
(http://i574.photobucket.com/albums/ss185/mposs/Save0002.jpg)
(http://i574.photobucket.com/albums/ss185/mposs/Save0003.jpg)
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(http://i574.photobucket.com/albums/ss185/mposs/Save0006.jpg)
(http://i574.photobucket.com/albums/ss185/mposs/Save0004-1.jpg)
(http://i574.photobucket.com/albums/ss185/mposs/Save0002-1.jpg)
(http://i574.photobucket.com/albums/ss185/mposs/Save0003-1.jpg)
(http://i574.photobucket.com/albums/ss185/mposs/Save0005.jpg)
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Brilliant, thank you so much.
Do you have anything for the later DR400?
I have a standard DR400 motor apart from cam , intake and exhaust mods and the clutch plates don't last too well on mine either!
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have you got the Motocross action DR400 article from 80/81?
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Leith, I've got the first part of it if thats any good to you.
Roger
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Cloggy , You need to put performnce clutch springs in . Change oil after every meeting as the cam tunnels are prone to wear .
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Leith,
I think I have a part of that article...not sure which one but definatly not the first one.
Will check and let you know.
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Oldfart
Performance re company or performance adjective?
And which cam tunnels, for the cams or for the clutch, if so do you mean the tunnels in the outer casing?
I'm not being difficult, just thick.
I got the RMC swingarm finally sorted, it was internally sleeved and slightly widened, didn't have to repin due to the DR bearings being smaller external diameter. I was charged for 1 hours work!
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re- cam , if you have altered duration and lift, you require heavier springs on top of valves (Eg performance springs ) mine obtained thru Tighe cams of Brisbane .... AS the cam is opening the valves earlier and closing later ( valve overlap) if the valve is lifting further .....you WILL REQUIRE heavier springs or you will get Valve float at high Rpm
Cam Tunnels .....groove in which your cam rotates in on head. Dirty oil is fed thru cam lube hole ( top of head ) which chews up the cam and tunnel . This problem was then overcome in the Dr 500 ,as they added a secound filter ( RHS case )
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Right OK
I've done at least 40,000 road miles with a Phil Joy [Protec copy] Road and Track grind
I use Protec alloy keepers and collets, I just got another set off USA ebay. I throw away the springs and use something that lasts out of a Ford pushrod 1600cc performance catalogue. They cost peanuts [at least they used to] and unlike the Protec items they don't sack.
I've never had a cam journal surface pick up, though they do get rattly, but then I change the oil often. When the bike was my sole transport I used Rock oil. I was a despatcher for a while down in the smoke and oil changes on singles were a max of 1000 miles, any make/model or they knackered.
Of course this isn't competition, and we don't have the extreme heat that some of you get, so the engines don't work so hard.
The cam I have gets rid of the dip in the powerband in mid range. Phil can still grind one up. For more top end I grind off the intake weir in the head, that doesn't have much effect on carburation
I did briefly try the cam with standard springs but got bounce. The Protec grind has a bit more lift and a lot more duration but the DR top end doesn't seem to suffer from heavier valve springs knackering the journals.
Megacyle list for this model but the exchange rate has gone back up.....
I would like to source better clutch springs. The suzie items sack pretty fast.
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Clutch springs in mine don't show any sign of sag , bike is thrashed at regular Mx meetings. Springs are std Dr 400 and checked at Xmas when motor was given freshen up . Check plate thickness ( 2.65 - 2.95 liimt =2.35 ) ......clutch spring length new = 40.5 limit = 38.5
the above is for DR 400
Sp 370 has a different spring tolerance new = 40.5 limit = 39.1
Generally the clutch on these old thumpers are more than adequite to cope with exta HP gains
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I've got a box of clutch plates, all well within tolerance and all pulled due to slippage. Put new ones in and slippage stops. I've never got to the bottom of it. I don't use aftermarket oil additives, just mineral oil.
The springs do sack eventually though.
Recently I've set the motor up with a smaller carb. There seems more low down grunt and it starts to slip after a very few thousand: before the plates would last well over a year.
I was out in the wet recently {Wales} and noticed that it went sideways at a touch of the throttle, this is on road with road wheels. I'm still waiting for the {hopefully} right fork springs to arrive.
Have you got fork springs you're happy with yet?
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Fronk forks ??? you trying to wind me up ;D still not happy with . Last meeting, I had what I thought all sorted out untill after secound race I had noticed they where bottoming out over small jumps and at the end of the meet the seals had shit themselves ( all balls triple seal ...red )
Back to the drawing board
Maybe change your brand of oil and see if slipage stops ..... most of my power is at mid to top end ( cam profile )
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I've tried that. At present there's only a touch of slip when the engine is warming up. Once hot it doesn't slip.
I've ordered a set of fork springs. When I get and try them I'll let you know.
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have you tryed the Leak Proof seals or plain old OEM?
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MotocrossAction article please? :) :) Anyone? :)
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Hi folks!
Much good useful reading in this thread. Haven´t had the pennies to invest in a users manual yet, believe me I will, so my question is if there´s anyone of you sitting on a DR400 manual and is willing to scan the elecrical wiring diagram for me? I would be eternally thankful. Heading for winter in Australia, soon summer here and I haven't gotten any of my bikes in running condition, guess that´s the downside of being a parent, if I´d only known ;D Managed to score a ´85 RM500 front forks and now looking for a ´84 front hub to go with it. After that I should have all the parts for a complete bike except plastics and decals which are easy to come by. Guess I know what to do this autumn/winter, besides being a dad...
So long for now!
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Jens, Yes I have a CLYMER service book which has a wiring diagram on the last page.
Will get me daughter to show me how to scan and load onto site ;)
Me thinks that the RM 500 forks might be too tall, and you would need a step ladder to mount your bike ?
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There are 2 types Dr 400 and Sp 400
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Sp 400
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hey old fart line me up for a beer at CD,shame i did not keep maico spring specs for DRM they were great and the envy of many TT riders who rode the drm
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Bazza, that sounds like past tense. Have you sold the DRM?
I'm still waiting for my maico springs to arrive......
Jens. hubs are available new from Crooks suzuki in the UK. Martin may well do you a deal. The hub is identical to the RM125. It's the brake backing plate which is different. Martin should have these as well. What are no longer listed or available new are the cams and lever assembly that fit in the back plate. I have to say the end result is not particularly impressive, even with after market specialist shoes and skimming.... I don't think this is much better than the original SLS DR brake
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Thanks a LOT Oldfart! And give my regards to your daughter as well ;D Yeah, the bike might be awfully high but I´ll bring a ladder when ever time to mount. Also been thinking about moving the footrests backwards, did that on my Curtis and it turned out a much better ride, easier over jumps, easier to balance. Any of you ever done that? and what´s your input on that? When it comes to forks I´ve found two other interesting deals for 82/83 RM500 forks so I´ll see what I´ll end up with. Propably a million other things I wanna ask but I´ll get back to you all. Cloggy, thanks for the info on the hubs, if I won´t be able to score a hub togehter with the forks I´ll definately get int touch with Crooks, the DR400 hub is big, awfully big and propably weighs there after. Ooooh, one other thing, the kickstarter on the DR400 is that the same as on the RM models? same splines?
So long for now folks!
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Dr 500 use the same kicker, Rm 79 -80 are about 100mm shorter and fowl with the frame- plus I recon you need the length to kick em over :D ....Yes I moved my peg mounts back ( 25mm ) so as the rear bolt is inline with the down tube, bike handles better . Down side kicker has a shorter stroke and your boots wear the shit of of your side covers .
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My thought on the pegs... I skipped the -85 forks for a pair from -82 including wheel. I guess that´s for the best since the bike is from -82 aswell. You say I wear out the plastics with my boots! Well, off they go ;) Thinking about the kicker, engine turns over really easy thanks to the decompresser and I can score a NOS RM kicker quite cheap AND my "old" kicker isn´t an original and looks like shite, pardon my french... Really looking forward to this project. My Curtis, which is undergoing renovation, kinda died out on me a couple of years back AND I´ve been living in a flat without garage AND becoming a parent adn so on and on... Moving to a house this fall with a brand new double garage! Which means I can finally relief my mother from a couple of other projects and my old Lotus Elan +2. Life is sweet ;D Once again Oldfart, thanks for the scans. O yeah, talked with a specials bikeshop the other week about my shocks. They said they could shorten them for me which means I don´t have to look for new once (got a pair of Ohlins piggybacks from a Husky in decent condition) and thus saving a couple of pennies. Sometimes things go really easy 8)
So long folks!
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Bah!
I always forget to ask atleast half of what I wanted to ask... Anybody know the axle diameter on a 1980 RM250 rearhub? And I would be pleased to know the oil amount for a 1982 RM250 fork, in milliliters, liters, centiliters or whatever as long as it´s according to the metric system... heathens ;) I guess this is a job for Oldfart, I kinda see him like bicycle repairman in the Monty Python scetch. Divine powers when it comes to old bikes ;D Well I guess that´s all for now, in an hour or two I´ll propably remember all the other stuff I wanted to ask...
Full throttle folks!
Ooooh, yeah, now I remember. What´s the difference between a two stroke and a fourstroke carburetor? Is there any difference at all except for the obvious like jetting? For instance my Curtis Honda utilise a Mikuni VM 38, could I use it (with different jetting ofc) on let´s say a Husky CR390? Not that I would ever want to though... And more so, what carb you guys reckon I should use for my DR400 engine, I was thinking like a VM36.
Over and out
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1980 rm 250 rear axle size is 15mm , i went onto www.alpha-sports.com and looked up rm 250 on parts catalog clicked on rear wheel and clicked on wheel bearing and it gives you the bearing sizes 8) thats how i worked out to find the right rm wheel to suit my DR 500,rm 250 1982 fork oil should be 178mm down from the top of the fork with no springs in and compressed , or around 425mm of oil in each leg by memory ;D
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Bearing size 6202
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You really can find EVERYTHING on the internet ;D Forums are just for us lazy bums... Thanks Mick, did you get the mail I sent you? If not I´ll resend it, hotmail lived a life on it´s own the other day...
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Yes jen got your email thanks :)have you got any spare swedish blonde hotties to send to aussie land for trade on DR info ;D
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Mick! There are heaps of them along the streets now in the spring ;) See If I can trick one to go to Aussieland.
Full Throttle!!!
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Himmmmm new job tour guide for swedish blodes thanks jen 8)
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White Bros used to do a 36 mm Mikuni carb for the DR400
I have the carb body and most of the internals brand new. What I've lost is the jetting specs and White Bros has been sold. However there are jetting specs for the XT 500 for this carb to be found on the internet and they may not be too different. For this carb to work I reckon you would have to have a fairly modded motor or it would be likely to be slower [on tight tracks at least].
This carb was used in conjunction with a race cam, ported head [intake weir ground off], 420cc high comp piston and a megaphone!
Past tuning attempts with the XT in standard capacity found the 36 to be too much carb, with power down virtually everywhere against the standard late model 34mm. Apparently the late model XT OEM34 produces good power but is difficult to rebuild, thus most people stick on the aftermarket 36 which is a very very simple carb. The aftermarket 34 has been said to not run cleanly for some reason, not for the XT at any rate.
Now the standard DR400 comes with a 33mm carb, has a bore 1mm more than an XT, but a shorter stroke.
However the jet needle on the 400 is a single taper and as soon as I did any more than take off the intake snorkel inside the airbox the jetting went haywire , or in standard english Jens it went lean to rich or the other way round all on the jet needle. Idle was close and so were main jet and slide cutaway.
The single taper needle profile stopped working when I opened up the airbox intake.
I had a spare SP370 carb so a I put that on and it was waaaaaay faster. So I dropped the needle one position, took the main jet down two sizes and later put in the idle jet in from the DR400 carb, and it carburates very well.
With hindsight I should have upped the main jet back to standard after I put the two size smaller idle jet in, but by the time I found this out it appeared to be running happily still, so I've left it alone. I now have bought two more 370 carbs on UK ebay, as the 370 has a two taper needle which was just made for the 370; so they come with the carb or not at all!
The standard jetted 370 carb also works fine [ just down a size on the main jet] with just a K&N airfilter and no airbox on a bog standard motor. I ran this combo in a DR400/Maico sidecar combination for several 1000 miles 15 years back. What I haven't done yet is switch the needle/needle jet from a 370 carb to the 1mm bigger DR carb to see if that works. The carbs use different diameter slides so it is not 100% that it will.
As the DR400 was only sold in the USA for one year there is almost no internet knowledge to be had from the USA.
I've trawled and trawled the Internet seas but never found any helpful engine tuning info.
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Another one for ya:
I need a 17mm rear wheel axle at 300mm length (not including the bolt head) otherwise I´m screwed. I know that some DR600/650´s and Honda XR600 axles are diameter 17 but I don´t know how long those are... Any suggestions?
What I´m looking for is a 17mm axle that´s as long as a RM250 1980 rear axle, so... how long is a 1980 RM 250 axle?
Regards Jens
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Hi all,
After seeing a couple of DRM400's here in NZ at VMX meetings I've taken the plunge and got hold of a 'T' model 1980 DR400 to give it a go myself...
It already has 36mm PE forks fitted.
After reading the Motocross Action articles on a similar bike this is my plan so far (luckily I have 1 1/2 79/80 RM125's and about 3/4 of a PE175 for parts)
Fit some 38mm forks from an RM (possibly front wheel to save some weight)
Fit either a PE175 or RM125 swingarm (probably PE due to shock mount positions)
Upgrade shocks (dont know what length til I fit the swingarm)
Fit an RM125 rear wheel (DR weighs heaps with the cush drive etc)
Replace collector box and std silencer with a pipe from the end of the std header to an alloy muffler.
May fit a 36mm mikuni (white bros type)(slim chance of one off a TT500 at the moment, but anyone know the white bros jetting specs for the DR?)
Can I fit a 34 or 35 mm Kehin of a 2 stroke? or am I being very dumb?
Any good sources for a Cam?
So, have I made any huge mistakes so far with that general plan?
Any advice, experts of the DRM400?
I'll put some pics up when she's done... If she's done...!
Thanks guys.
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I'm a rubbish offroader but I've fiddled around using all the below
The PE 175 swingarm will fit the DR wheel assembly [which is heavy] without modification. However it needs 2 top hat spacers turned up to fit the DR frame which has a bigger swingarm spindle. It's dead easy to do and you end up with a slightly longer swingarm, at least an inch. Some guys over here thought that was an improvement. You then have to use a much shorter shock length, unless you are have 34" legs [The standard steel swingarm will go to 16.5 inch on the shocks and you need to do this as the head angle is a touch slack as standard and there isn't much room to steepen it ].
Negatives are a more spindly swingarm pivot which in theory might get through bearings, probably not a problem for track use; and more importantly the shocks are more upright and have more loading so they work harder and need much stronger springs
The PE250/400 ally swingarm uses the same swingarm pivot size as the DR and is otherwise identical to the PE175
I have a RMC [250?] ally swingarm to go in. The swingarm pivot housing is weak, as Old Fart has stated. However all that is needed is an internal slightly longer sleeve inside the housing, into which you then fit the standard DR bits. An engineer charged me one hour to do this, again a doddle
However the wheel spindle end is different and that may need fiddling with dependant on what wheel you put in. As standard, DR stuff doesn't fit, though the width is fine
I did recently pick up a wheel spindle for a supposedly 250 RMC ally swingarm. I took it off myself but it turned out to be smaller diameter than my RMC swingarm, so that may need checking
By the way the RMC swingarm length is identical to the DR so the only advantage is weight. It uses [as Bazza has stated] a 398mm shock length, but that's from memory so you'll need to check back through this thread.
Robin of Falcon Shocks reckoned the spring rate needed was so close to standard DR as not to matter. I've had no time to check yet
Early 38mm forks will work with standard DR wheel. Late ones with the 4 bolt clamp use a bigger wheel spindle. You can get the early 36mm triple clamps bored out 2mm, Suzuki appear to have done this themselves!
If you use later 81 on beefier triples the early DR steerer [when swapped over] only just catches the thread. I don't know if the late triples work with the early wheel.
I may still have the jetting specs for the 36 Mikuni. Tom White sent them to me on a hand written note. Thus far In clearing the bottom half of the shelves and draws I have found a missing letter from 1978 so there is hope!
Old Fart got his cam from Aussie Tighe. I got mine from UK Phil Joy, and USA Megacycle still list for the DR. As already stated you will need stronger valve springs
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Untold gems in there ;D
Thanks.
Seems like I'm on the right track. I will be using for MX so The extra length of the swingarm will be useful in both raising the ride height, and quickening the steering. Not to mention the weight.
I have no shocks yet (other than some el cheapo 16 inch ones on at the moment and some blown PE units. . . An upgrade is on the cards - anyone whos made this swingarm mod? What shocks, length and, I guess more importanatly, spring rates did you settle on ? ???
Be awesome to get those carb specs when you find them. 8)
Thanks again guys
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The PE250/400 ally swingarm uses the same swingarm pivot size as the DR and is otherwise identical to the PE175
no, the PE250/400 alloy swing arm is a lot more beefier overall than the PE 175 alloy swing arm.
for valve springs try R&D valve springs from Serco or www.bbimporters.com.au
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Sorry I haven't seen the two side by side
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Hi,
finally getting started, well got all the bits out anyway...
Has anyone had any luck with fitting a Mikuni 34mm VM(round-slide) carb to one of these? Seems like a good idea as I dont plan to do enough to the engine (i.e. cams, flowed head etc) to warrant a 36mm. Also it would meant that I could fit an RM125 airbox and filter that I have, instead of the exposed K&N currently on the bike.
Latest plan is the PE175 swingarm and rear wheel (has the cool brake and sproket on the same side setup!) early 38mm RM125 forks and front wheel from the PE as well...
Any further thoughts on the carb issue?
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i remember selling 34mm TT500 carbs to the 370 boys years ago and they liked the 4mm up grade and being from the same family of mikuki they fitted straight on with no mods at all,no one ever bothered rejetting and they seemed to work well could be a hassel free cheep up grade
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Sounds promising!
Except my 34mm is off a PE175. Would you know where I can get those jetting specs for the TT500?
I'll have to get some before and after pics up soon.
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Don't know if this helps, but have copied part of a DR370 Engine hotup article from Nov 1978 Motorcyclist mag. They took the engine out to 450cc and this section was about carburetor specs.
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standard 34mm TT500 carby jet specs are 30 pilot 210 main 6h2 needle
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Awesome!
Thanks all. 8) ;D
Should save me a few $$ on a 36mm carb. Now I'm off to the garage to start pulling the old DR apart. Got to be better than sunday afternoon TV ::)
Spose I'd better consult the masses on a colour scheme. Currently white with a blue frame. although may strip and polish the alu tank.
Options are:
1. RM yellow and black
2. Blue frame with white plastics (the wheels I have are anodised blue rims as well 8))
3. Hot rod style: Red frame and silver rims and tank,with flat black everything else (ey wonder if I should whitewall the knobblies :o)
What do you reckon?
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Gavin white wall knobblies cool 8) NZ hot rodders will love that , i reckon yellow RM colour and blacks the go :o blue rims, Ive got a DR500 white & black with black rims kiwi built to ;) go hard bro, choice one cuzzie, cool, thats mint, sweet as, howzit, miss those kiwi words :D good luck send me your email and i will send some pics ;)
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The standard DR370 32mm and DR400 33mm slide carbs have an elongated throat [it's a lot taller than it is wide] so it's difficult to know how they flow compared with an aftermarket 34.
Also the DR400 engine was beefed up a bit in [if I remember correctly] both the bottom end and gearbox.
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Whilst I have the bike apart I will give the motor a full service. Valve clearances, rings, maybe a piston, and some fresh oil and filters. I will then try it with both the std carb (33mm) and the 34mm (now I have the jetting specs ;D).
I'll let you all know when I eventually get to the test run stage. ::)seems like a long way away!
I'm not looking to hugely boost the HP with cams and headwork, just looking for a nice stong, smooth motor. I'm going to focus more on the handling and weight issues.
The std flywheel seems HUGE! has anyone here tried lightening it at all?
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Gavin, most of your power gain will be in a little bit of port work - 3 angle valve seat - new valve springs .
Put a custom pipe and YOUR STD carb re- jetted and you will have more power than you can handle ;)
lightening your fly wheel will give your more top end revs with a loss in bottom end torque.
Most of my overtaking are at corners ( engine braking unreal hardly use the brakes ) and on the exit low down torque while short shifting up thru gears ;D
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Thank you Old Fart, a larger carb only makes sense with a radicaly modded motor, but it's a persistant myth that a carb on it's own makes a big difference.
The difference tends to be the carb finally working at high revs after underperforming everywhere else, hence the power step.
The stock DR is unbelievably bunged up as standard, hence when modding the carbs to adjust for intake and exhaust mods I've always had to jet down, opposite the norm.
The Suzuki manual is very clear on a 3 step radius at the valve seats.
Have you removed the weird weir in the head's intake or have you left it alone? I'm soon putting back together another motor so I'm interested in your experience on this.
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Wier is removed :) exhaust port at head radiused - plus material taken away from Valve stem guide .
Your spot on with carby jetting .....better results with jetting down = equals better power curve
When you get closer to make head mods send me a PM
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put a 36mm pumper that ray ryan donated on my original DRM,only had to change main jet and not a miss to be had,also lightend the flywheel for bit more snap and motor still pulled like a whalan school boy
Bazza
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Not saying it doesn't work well Bazza, just that it's unlikely to be any better overall than a properly tuned standard carb.
Manufacturers aren't dim, they put on the correct size carb for the engine in the first place
Top OZ tuner of XT 500s uses the standard late model 34 carb.
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36 flat slide ( i found jets i used) was with lighten flywheel, 3 angle valve job,big exhaust and lite porting,with very mild cam.All up a great package.Only sold because to many toys and the Shelby motor was ready to drop in the Muz.
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We've talked in the past of the difficulty of finding suitable fork springs when using 38mm forks
I've now done 3 rallies [UK forestry events for muppets and smokers, -and good blokes on HP2s] and the Norman Retro Enduro. I've got the heaviest Maico springs that were available for 38s [not the same as 40mm springs]. I reckoned that they were supposed to be somewhere around 28lbs per inch, give or take a lb. They've been just right with no preload and no air in 1981 RM125 38mm forks. The Cartridge Emulators have got rid of the spiking.
I went to watch Farleigh castle international twinshock and a Jean-Francois turned up on an immaculate DR engined RM with Fox shocks and Simons forks, and a 38mm carb on an otherwise bog standard engine. He bagged around 7th overall over the two days. He bent both axles on the jumps though.
He altered the chassis with GN400 bottom frame tubes.
http://i694.photobucket.com/albums/vv306/clogy/farleigh09029.jpg
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I've got Wilbers p/n (PD-03) Honda XL600 83-84 model springs in my RM250T 38mm forks, works out at .43 spring ratio which is about the heavy'st you can go.There quite a long spring so you may have to shorten them. I have PD valves as well. We worked out the std spring rate was .33 and thats why there too soft, and of course we all weigh 25 kg's more now as well !!!. Wilbers are over your way, they have a web site. Cheers John.
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I think my springs were marked 49, which comes out to just over 27lbs per inch, assuming the spring rate is accurate. They needed a two ish inch spacer to take up the slack on a 10 inch travel fork
I weigh the same as I did in my 20s about 12and a half stone with riding gear and tool bag
I think the DR may run the engine closer to the front wheel than the XT, certainly there's not much room to steepen the head angle: so maybe that's why it needs a heavier spring
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Such a good thread I thought it should be bumped to current
Thank you to the major contributors for their hours of R&D
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I just reread the postings about carbies and thought I'd put in my 2 cents worth. Mine has a 400cc SP370 motor with a free flowing exhaust and have swapped between the standard narrow oblong bore carby and a 36mm Dell Orto pumper carby for comparison purposes. The carby is obviously made by Dell Orto for large cylinder capacity 4 stroke road bikes, and I bought it from Geoff Udy in 1979 as a kit for the SP370 and it came with an adaptor to fit it to the head.
The reason I got the carby kit was not for more power, but to fix the stalling tendency when riding over big logs (sudden throttle opening at low revs). It is magic for this and the motor is highly responsive to sudden throttle opening at all RPM. I never tried the Dell Orto with the standard SP370 exhaust, but with the free flowing exhaust on the RM hybrid bike, it is vastly superior to the standard carby at all RPMs.
The only downside of the Dell Orto is the fuel economy. This hybrid bike was my enduro and trail riding bike at the time, and I found the dirt road fuel economy went from 100 MPG with the standard carby, to 60 MPG with the Dell Orto. I had a PE250B (alloy) tank that I used for longer rides, but it is easier to ride with the RM250C tank, because the seat is closer to the front of the bike with the RM tank fitted.
I read a few people have lightened their flywheel for better response. I find that with the way mine is set up, I would actually prefer a heavier flywheel to make it nicer to ride in loose/tight/steep terrain. However on an MX track where riding precision is not as critical, the motor is fine with the standard flywheel weight.