well on my 02 raptor one of my engine brackets came loose and that was rattling when i reved it netural and then when it came out of that high rpm it didnt rattal anymore try that tighen all the motor mounts first my loose motor mount was under the gas tank

just letting u know

 

Front two bolts on your GYTR Full Skid are your problem. Mine loosen up and only rattled when I reved it up. Sounded just like internal (valves). I freaked until I pushed on the skid while throttling in neutral and it stopped. Thing is it still rattles even with it tight....so I am gonna put something in between there to quite it down.

 

Just to update everyone, I jetted the quad with GYT-R kit, put in a fresh spark plug and now is running great. There is still some vibration, but it doesn't scare me like before because the engine is running so strong. I guess it has to be one of the motor mounts or skid plates. I wish I would have tightened all the motor mounts before I put everything back together.. lol. Thanks for all the help guys, Ill repost to this thread once I have a chance to tighten skid plates and motor mounts. I am thinking about getting some rubber washers for the skid plate to cut down on their noise. Anyone try this?

 

I didnt use rubber washers but used some one sided rubber that I stuck around in different parts of the skid plate to mesh up with the frame. Its as solid as it will ever get now.

 

You will not get detonation from running to high of an octane gas. You get detonation from running gas that has a lower octane than what your engine was built to run on. I don't think the 110 gas has anything to do with the problem you are having.

 

Well I tightened up the skid plate and now the vibration is down to only occuring during very high RPMs. I realized that on the front of the skid plate there is a little play on the front in between frame and bracket is w/ the washer. I was taking out the bolt to replace the aluminum washer w/ a rubber one I got from the hardware store and the damn aluminum bolt broke. Its the 6mm 10.9 torque aluminum bolt that's all over so I'll just pick some up @ yamaha and replace the washer with rubber one so that should take care of the last bit of vibration.

While I was running around today, I stopped off and picked up the K&N breather filter that sixsixT recommends.