96YamVmaxXT
New member
What is the max rpm these engines can handle? My primary clutch is in rough shape, I got it so it works, but its revving up to 8700 rpm under full throttle (I stopped after the first time it did it.) I plan on replacing the whole primary due to the fact its going to cost me about the same to fix this one. Any thoughts?
no1chevyboy
New member
the stock rpm is 8000, but with gyt twins and head gasket mod its 8300+-100 according to my yamaha tuning specs. that came with pipes
daman
New member
your waaay over reving....stock spec shift out may be 8000 but a 600 twin makes peak HP 96ish @ 7500-7800,fix your clutch before you hurt your self.96YamVmaxXT said:What is the max rpm these engines can handle? My primary clutch is in rough shape, I got it so it works, but its revving up to 8700 rpm under full throttle (I stopped after the first time it did it.) I plan on replacing the whole primary due to the fact its going to cost me about the same to fix this one. Any thoughts?
no1chevyboy
New member
hey daman were did you find that the peak is so much lower ,at a yamaha shop by me the racer said its way higher around 8500-8600, just asking because your both so far apart? no offence intended my paper work says that 94/95 peak was 7650 stock
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96YamVmaxXT
New member
Thanks guys, I plan on replacing the clutch with a comet 108 if I can find one.
daman
New member
No problemno1chevyboy said:hey daman were did you find that the peak is so much lower ,at a yamaha shop by me the racer said its way higher around 8500-8600, just asking because your both so far apart? no offence intended my paper work says that 94/95 peak was 7650 stock

On a stock engine he said 85-86?? lol, maybe with pipes but any tuner knows thats not correct for a stock sled,stock exhaust, i've seen dyno sheets that show otherwise,peak tq is around 75-76 and peak HP is 7800,back when i was dialing mine in i clutched to run 7800 and it ripped.
pinned outa the whole you want 73 to 76 then climb to 7800. for stock.
daman
New member
why??96YamVmaxXT said:Thanks guys, I plan on replacing the clutch with a comet 108 if I can find one.
no1chevyboy
New member
ya i beleive he was talking about piped,but are they all the same 94-96 the tuning says 94-95 7650 96 8000 stock? just wondering
daman
New member
Right yes in that area but 8000 is over rev'en for a stock 5-600 twin,if memory serves me right it was a read from Dynotech or Bender one of the two..no1chevyboy said:ya i beleive he was talking about piped,but are they all the same 94-96 the tuning says 94-95 7650 96 8000 stock? just wondering
no1chevyboy
New member
ok thanks
daman
New member
no1chevyboy was that tq or HP in your book??no1chevyboy said:my paper work says that 94/95 peak was 7650 stock
96YamVmaxXT
New member
I was thinking about replacing it with a Comet but I didn't know they shut their doors. My clutch needs rollers and bushings, flyweights, and the sheaves are pretty worn. I think it would be more cost effective to replace the whole thing. Anyone have any good used ones? How bout using a Polaris P85?
no1chevyboy
New member
that was shift rpm(wot)
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daman
New member
yes you may be be better off picking up a good used one but they range from 140- 170 bucks, then you'll need to clutch it for your application. check the site here or post a wanted ad or ebay,etc...id stick with yamaha.96YamVmaxXT said:I was thinking about replacing it with a Comet but I didn't know they shut their doors. My clutch needs rollers and bushings, flyweights, and the sheaves are pretty worn. I think it would be more cost effective to replace the whole thing. Anyone have any good used ones? How bout using a Polaris P85?
thanksno1chevyboy said:that was shift rpm(wot)

Hey VmaxXT you know that the bushings are replaceable right? It'll be about 1/2 the cost of buying new rollers and weights. T
96YamVmaxXT
New member
Yeah I do know that, but considering the condition of the sheaves Its not worth spending the money on the clutch that's on it.