What do I do?

[harrybosetti]

I have a 2001 CR-80, I recently put on a FMF Fatty expansion chamber and a FMF Q silencer. I ride my bike at about 3500 feet. Ever since I got the new setup, I've been having a problem with the topend power of my bike. Here is what happens. I hit the throttle and accelerate as normal, rpm's increasing normally, then, right before that burst of speed, the rpms flatten out, then the engine sounds as if it's waivering. I have the throttle full open but I just can't get the engine to go past this certain point?

What do you guys suggest I do? Any help is much appreciated!

 

[marcusgunby]

try to richen the jetting a little on the main jet.

 

[harrybosetti]

How much would you suggest? 1 up?

 

[reelrazor]

Wavering, little surges like it wants to pull but can't? Is making revs but not power? Marcus has got it right if that's the case. I would buy the next two jets higher than what's in it, go up one step and try it, and if it gets better but not gooood, go the next higher.

THEN put a new plug in it, try it and when you are in top gear in 2nd or 3rd, clutch it and hit the kill switch at the same time. When stopped, pull the plug and look at it. The porcelain should be cardboard brown, no lighter.

you may need to make a small adjustment to the needle, but get the main big enough to start with.

 

[harrybosetti]

Well, it sounds like it's not even getting the rev's? I only weigh a hundred pounds so it's not like Im too much of a load on the bike. So yeah, it sounds like it wants to hit the "powerband" (I think thats what the turbo-like thing is) but it just can't rev high enough to hit it.

 

[RoostRider]

have you cleaned your air filter? how about your carb?

If it changed all of a sudden and you changed nothing, I doubt it is your jets.

 

[harrybosetti]

It changed after I put in a new exhaust system.

 

[RoostRider]

Then jets are a definate possibility and should be refined anyways. Do the jets and let us know how it goes.

 

[harrybosetti]

will do, thanks for the help everyone.