Seems to be coming from the engine. It goes away if you put your create a little backpressure by lightly putting your hand against the opening from the exhaust.

Do the exhaust valves need adjusted? Could it be internal to the exhaust? I would say I have about 40 hours of riding time on the GYTR tip and have never repacked it.

Thanks,

NotuRaptor

 

Does it do it only during warm up or all of the time?

 

It makes the noise at idle all the time whether warm or not. The noise is definately louder when you stand on the right hand side of the quad versus the left.

I adjusted the valves today. The intakes were tight and the exhausts were still okay (never changed yet and I've had this Raptor for over a year). This made no noticeable change in the noise.

I used a piece of garden hose to listen through to help isolate the noise. It seems to be coming from inside the headpipe (not the GYTR tip portion). It runs great. Checked for loose bolts. Adjusting the idle up or down makes no difference either.

I am getting closer to taking the quad to Mickey Dunlap for a valve job, new springs, and installing the 2002 gear set. I am trying to get the spare 400ex in shape before I let the Raptor go for any period of time. Maybe he will be able to find it.

/Jon

 

This might sound stupid but I also have the GYT-R slip on and the spark arrestor screen rattles. That might be it?