LT80 gearing

[smr]

I have a problem with our LT80 and I can't figure out what's going on. The quad takes off great and will bump the rev limiter but has no top end speed. I am running the 420 chain with a 15tooth front sprocket. He does great in the turns but they run away from him in the straights.

the cyclinder has been ported and there has been clutch work. It almost acks like the clutch is not going into high speed.

[wilkin250r]

The problem is in your tranny.

The LT80 uses a CVT, which stands for Continuously Variable Transmission. It's job it constantly vary the drive ratio to keep the engine at a constant RPM, and the specific RPM is determined by weighted rollers.

If you're ported, but no top speed, it sounds like your CVT isn't properly tuned to keep the engine at peak power. You might have peak power at 9000rpm, but your CVT is holding your rpm at 8000rpm, and thus not achieving peak power.

To type the whole thing out here would get very boring. Here's a link, let us know what you find.

http://www.off-road.com/atv/kidskorner/clutching1.html

[smr]

Thanks for the link...I think I learned something.

I removed the case hit the throttle so could view the clutch. I noticed the belt is not coming all the way up on the pulley. There is a good 1/4 inch between the belt and the top of the pulley at full throttle. Is this normal?

I removed the clutch and one of the rollers has a flat spot. I gonna replace the rollers and see what happens.

[LT80]

Did Chris (CGR) do your motor work? Knowing that will help me help you. :) I'll presume it is built by Chris because I see you mentioning him in another post.
I don't see a flat roller causing that problem.
1/4 inch from the top of the outer pulley half? That would be normal.
Ok,,there is NO rev limiter.If it's blubbering then I'd look into the jetting.
Your quad is not getting down the straits cuz the 15 front is HUGE!! It's bogging the motor instead of letting it wind out.
for a stock motor a 15 would be acceptable, but not a modded motor.
FYI: it's a 428 chain size or 520.

[smr]

428 chain.

No Chris didn't do this motor. I bought the quad this way.

We usually run the 13, 14, or 15 front sprockets and we have never had the problem. Like I said..it runs reat off the bottom but it has no topend.

The 1/4 inch is from the top of the inside pulley. I also forgot to mention that I am running only three rollers.


thanks

[LT80]

3 rollers explains that very well IMO. I feel there is not enough roller weight to get the clutch out to max travel/speed, at least with the current mods producing xxx rpm's. Try 4 rollers.

[smr]

LT80..thanks for your help. I installed three more rollers today and gained huge on the top end.

It does seem to have lost on the bottom end. Would you recomend droping down on the front (still running the 15) our should I remove 2 rollers.

[Livin4Real]

what weight rollers are you running?

[smr]

stock

[LT80]

Try running 4 stock rollers. That should be close.:)