OzVMX Forum
Clubroom => Bike Talk => Topic started by: VMX Andrew on February 22, 2008, 09:12:02 pm
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hi chaps...just bought myself some new boysen reeds off evil bay for the CR500 and was wondering if anyone has used them and found some so [called power gains] or are they just another rip off power rubberband ;D v8 vegetable jucie ;D type of gain.... ::)
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How far do you live from Hoony?
;D ;D ;D ;D
Sorry Hoony couldn't let that one go past
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Andrew I tried some and found they were crap,,, no wait super crap !! then I fitted V force and the bike is hauling ass now..Sorry to offer negative feedback, but they make the bottom end blubbery and very difficult to tune. Mine were fitted to a Yammie 465, but maybe they will work better on the CR??
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anything (pre81) I've ever fitted with Boyesens definately had a noticable gain. I can't comment on other brands or big bores as my experience with them is limited to 250cc and under and Boyesen's only :-\
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Pro Series carbon fibre are wait for it as good as most carbon reeds the dual stage ones ever so slight improvement on stainless.Top petal is very flexible and flaps around uncontrollably when revs rise.Thier RAD valve isn't in the same league as V-Force
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Mine were fitted to a Yammie 465
If you are not using them do you mind sending them to me so that I can try them in my IT250d please.
then I fitted V force and the bike is hauling ass now.
How do I find out which V-Force fits our old Yammies?
Can you tell me the model number you used in yours?
Thanks, Mark.
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Mark, PM me with the dimensions of your reeds ie. length width etc, I looked on the yamaha parts site and the prefix to the part numbers is different but the rest of the part number is the same as my 81 IT465 reed and reed assy. It may fit but its probably easier to measure first. If they are the same then maybe the V force reeds I bought will fit your bike. Any Yamaha experts wanna give their opinion as to wether the IT465H (1981) reed block will fit or is the same as the IT250D (1977) block or reeds. If it fits they are yours no probs, Mark I could post them but you will only know if they are gonna fit once you remove them.
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How far do you live from Hoony?
;D ;D ;D ;D
Sorry Hoony couldn't let that one go past
should i post a pic of the "Loz-Valve" ?
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Even a bus load of QC's wouldn't even attempt to wriggle out of the iron clad "commerial confidience" clause you signed Hoony ;D ;D ;D ;D ;D
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(in a Maxwell Smart voice) would you believe 2 lowly solicitors and a flunky clerk?
can i wriggle out of naming my second born after you at least.
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The IT250D reed block has distance between bolt hole centres of 71mm and 53mm.
This is also the same as an IT175J block that I have.
But the IT175J is broader at the base and so does not quite fit.
A Boyesen Catalog lists the 640 reeds for all IT250s and IT465s, IT425s, IT490s and some YZs.
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the loz valve - wasnt that the icecream lid conversion ?
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Mboddy send me your adress and I'll post them to you, you can PM your address if you want
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pitty us suzuki guys cant fit a V force. im still desperatley searching for a 6 petal DG reed valve for a RM/PE or a R & R Racing hi flow reed valve for a RM/PE. i will pay mega bucks if any one has one to sell! either of these reed valves are pretty much the only aftermarket part i can not find and its one of the last parts i want to find. pretty much every part i thought would be hard to find has fallen into my lap but not these reed valves
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Didn't see any ice cream lids Freaky.
No I wouldn't even believe a 12yr old debating champ who has watched every episode of Perry Mason, suppose it's better than the youngun being named CR, Mugen or H*nda Hoony ;D ;D ;D
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heres my bit nothing wrong with boyesen reeds they have been around for nearly thirty years
they were the hop up performance add on that was done to bikes like we ride now
they were used by the factorys and on works bikes 8) been using for years never had issue ;)
sure new carbon tech reeds are better but ??? ??? ???
i think v force are a bit sus
this is new tecnology on old bikes sure it works
but is it really legal
its a modern performance bolt ,on what does everyone think
also they are not available for all models
is this fair ???
speak your peace or forever hold your tounge :P
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In what way EXACTLY are V-Force 'sus'????
Only reason Boyensen would have ever been used on 'factory' and 'works' bikes was they paid .Plenty of things been around for 30yrs that fact doesn't make them better.Is it legal? Is it fair? Well considering anyone can buy and fit one in 5mins it is hardly unfair is it, in the same basket as YSS shockies. PVL ignitons & modern sticky tyres.If Tassinari don't list one get out your calipers and measure?
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Mark, I popped your Boyesens in the post today, should be with you in 3 days or so. Good luck with them, i hope they work for you. They are slightly blackenned from the oil etc but they are basically new , probably 2 hours on them at the most. Just clean up the thread lock that got squeezed onto the reed mounting holes.
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Thanks Tony. If they turn up before the weekend I'll try them at the Sunday Dirt Track practice.
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I'm probably not qualified to make judgement seeing I've only owned about 12 "Big Bore" HONDA's ::)
But I can tell you that they definately make a huge difference to the power curve over STD reeds
most you'll gain smoother power delivery, and more top-end as with STD reeds! They hit like a mule and sign-off early in the revs. So although they feel less powerful in fact they make the bike easier to ride thus
producing quicker lap times.
Do the test and check your times you'll be suprised!!! 8)
Big "can't ride CR500's for shit" Bill.
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Bill,
I'm with you, the boyseen reed's I have used where great, Increased bottom end and smoother out the transition between bottom end and mid range, mind you these where on early 90's 250 two stroke oh and a '81 dt 175!!
Don't own a bike with a reed cage now.
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I hate to go against the Establishment but my experience with Boyesen's, as stated above, was only positive. They have lived up to all expectations in anything I've fitted them to. I still reckon agree, one of the best and simplest $ for $ power improvements you can make..you 'will' notice the difference..maybe they spread the power better or only have better response..maybe they don't make any extra HP but once fitted they certainly feel like they do ;)
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I used Boysen reeds on my 500 Maico and noticed a distinct improvement off the bottom to the mid range. I'm not sure the bike was faster up top but it was sure smoother and got there a wee bit quicker. I've never tried V force reeds so can't really comment on them.
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ive fitted the dual stage boyesens to a few bikes and they do make a noticable difference and do what they are claimed to do. they might not be as good as other brands or reeds from the latest and greatest material but for our old bikes i think they are a worthwhile cheap modification and are what was used back then.
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Geez I needed a good laugh and reading all that I got one.
One would wonder why Boyesen made the 'Pro Series' if the normal ones were so good.
http://www.boyesen.com/cwo/OFFROAD#psreeds
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I haven't done any testing of reeds on dirt bikes but I have done a lot on Yamaha road bikes.
Original RDLC stainless steel; Good top end, bad hesitation just before power band.
RZ stainless steel in RDLC; Good top end, hestitation improved.
Late model RZ fibreglass; good all round.
Hi-Tech fibreglass; best low but reduced top end.
Boyesen dual stage without reed stops; good low and mid, but reduced top end.
Boyesen dual stage with reed stops bent to increase lift; good low and mid and improved top end.
Harpower thick fibreglass; great top end.
Carbon Tech High Tension carbon fibre; best top end.
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So Lozza, are you saying the pro series are no good too, or just the normal ones????
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My piston ported Maico goes well enough without reeds. I once built a reed barrel using Yamaha an MX250 cage and boysen reeds and it made bugger all difference. I buggered the originality on a rare square barrel for no noticable change. My mate had the same slack result with his Elsinore......Who needs 'em.
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My piston ported Maico goes well enough without reeds. I once built a reed barrel using Yamaha an MX250 cage and boysen reeds and it made bugger all difference. I buggered the originality on a rare square barrel for no noticable change. My mate had the same slack result with his Elsinore......Who needs 'em.
......Who needs 'em.???? All those 125 Elsie's four stroking away after been kicked in the guts ;) :)
If they didn't work I wouldn't think they would have been fitted to every two stroke produced in the last 30 years. Either they work to advantage or its the greatest con in history.
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reeds should give a boost down low but above that it's all piston ports' domain..if your bike had plenty of grunt down low already I dobn't (short for doubt and don't think or an uncorrected typo) fitting a reed would be advantageous at all. I like 'em cause my RM's like 'em ;D
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I am with Firko !!! None of my 754 motors use the flat pricks ..... :D
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Geoff the Pro series are much better.Helps the top reed flapping uncontrollably like a toupee in the wind.Reed conversions only work when the additional ports go in that otherwise wouldn't be possible without the reed valve.
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The reed conversion to the Maico did tidy up the bottom end a slight bit but then only when I switched to a Mikuni carby. When weighed up against the considerable welding and machining I put into fitting the Yamaha cage and the sacrificing of an unobtainable 350 Maico barrel, it wasn't worth the effort. I agree with what Lozza alludes to in that reed conversions to piston ported engines are often not successful. The only Elsinore conversion I ever saw that worked was Kevin Hortons radical methanol Elsinore that had been fitted with a CR500 reed cage and V Force reeds. Sadly the conversion was deemed illegal and later banished from the sport. Those GEM and Mossberger bolt on reed conversions aren't worth half of the silly money they get for them on eBay these days. I have a GEM DT1 kit that I'll keep on the shelf as a curiosity.
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mboddy did you get the reeds yet?
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Yes thanks Tony but not quite in time for the weekend. I'll have to try them later. Thanks.
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geeze i can even be bothered cleaning the air filter and you guys are all getting pro on reeds and shit. whats wrong with the steel ones ? if it came with it it stays on. and get a wipe with a rage if its lucky. you guys have way to much time or money or both. whats next crankcase suction pumps
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mmm i just might stick with the standard reeds after all... ::)
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whats next crankcase suction pumps
Reed block stuffers. :)
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Unfortunately Freaky racing is all about improving the breed. If you don't take advantage of what's on offer today that's your choice.Has nothing to do with money or time at all it's more about being smart.Using steel reeds is dumb/pig headed as they are just complete SHIT.
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mmm..... like they say historic racing is only in the photos. the gap between reality and history widens... actually some say its cheating but ill let that blow up in the postie scooter thread :O)
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In club races I guess we are all kidding ourselves, those that buy power parts and those that claim its cheating, because 5 or 6 hp aint gonna make a bees dick difference to who crosses the line first, its 95% rider that counts, its not uncommon for guys on really old no power no suspension bikes to thrash the crap out of guys with 12 inches of travel rising rate suspensions and 55 hp,, in fact in our club QVMX we have some guys that ride 1960sumpting BSA's that will knock the crap outa most guys on any evo or pre 85 bike, even on a track with jumps. When it comes to nationals with rule books I recon yes then it should be monitored just so that people know that there is a limit to go to.
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you beauty - finally got something to argue with Firko about :D - bit late I know but haven't been on the site for a few days.
Must admit Firko my 73 Elsie came already fitted with a GEM reed and has been ported/windowed/polished within an inch of it's life by the previous owner. But I can guarantee that it has made significant difference to my 250 compared to any other Elsinores in the club. I must admit (and boy I know I will get caned for this comment) I give away just a couple of kilos to some of my mates but the 250 (in a straight line anyway) certainly holds her own (and often better). It is crisper across the entire range and better off the bottom and just doesn't want to stop going. Addmitedly the guy before me had receipts for VAST amounts of money spent on it but the reed valve for me is a great addition - and thanks to Lozza for the new petals as spares for them are rare as nowadays.
I have ridden other stock Elsies and they aren't in the same ball park. ;D
FWIW
Rossco
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Ican remember in the late 70's the fitting of boyesen reeds was always the 1st mod the ol man did 2 my yz80's. Also ithink its just peace of mind knowing your not goin2 lunch your engine if 1 lets go.