completely stumped. 2001 elite s lost power and speed.

[Simonsr50]

ok hear me out. I have a 2001 elite sr50 and a 2001 elite s 50 which i unrestricted. I have made them the exact same from clutching, gearing, jetting, and and box mod. they both used to be the same speed but recently it seems like the S is getting slower but only by a couple MPH. I thought at first it was clutching but when i switched the clutches it still was slower, so i changed the exhaust and still nothing. i am completely stumped. what else could it be. it idles fine, sounds good and they both have identical compression. any thoughts ???

[scottinscotty]

variator weights worn, dirty air filter, and or worn belt

[dv/dt]

worn rollers?

[Simonsr50]

rollers are brand new in both machines with only 100 miles on them and belts are too. air filter is perfect. I feel like i have checked everything, what about reeds? could they be bad or something

[bakaracer]

if its only a few mph that you lost then no. if the reeds was bad the bike would run real crappy. pull the rollers out and check. also measure the width of the belt.what brand belts do you have in the bikes? some aftermarket cheap chinese belts will wear really quick.

[dv/dt]

tire pressure?

[yamahauler660r]

variator weights worn, dirty air filter, and or worn belt

x2 & A fresh plug, complete carb clean (I use a single strand from small stranded wire)

Swap ICM's then coils??

worst case, rings and or head gasket?, crank seal(s)?, reeds? etc....

[Trafficjamz]

x2 & A fresh plug, complete carb clean (I use a single strand from small stranded wire)

Swap ICM's then coils??

worst case, rings and or head gasket?, crank seal(s)?, reeds? etc....

Belt , tire pressure, or carbon build up in the pipe is my guess

[yamahauler660r]

so i changed the exhaust and still nothing.

[yamahauler660r]

rollers are brand new in both machines with only 100 miles on them and belts are too.

[tru72]

Did you check the compression of both bikes. also the exhaust port might be full of carbon build up as well...
Aloha
D

[Trafficjamz]

@ yamahauler660r

The OP said he lost a few MPH, not that his bike runs badly.

That is why thinking it is the carb or reeds is

And the ICM???? If you mean the CDI, that is still way off base.

bad cdi or coil does not cause you to lose a few MPH.



@ Simonsr50

Swap the entire trans setup from one bike to the other.

If the problem follows the trans then you know it's the trans.

My money is still on worn belt or rollers.