Hello everyone, first of all let me introduce myself, my name is Sam, I've been riding my 02' thundercat (UK spec) for half a year now. I have come to you in desperate need of help.

As the topic suggests my bike is vibrating when accelerating in 4th gear. This is the only time it happens, and it vibrates lower down in the rev range, with the vibration being more prominent the harder you twist the throttle. As the revs get into the 7k+ range the vibration doesnt appear to occur.

If I could describe the vibration, my closest description would be that it feels like something could be grinding.

I'm dreading that it may be a serious problem with the gearbox, although I'm praying its not that serious.

Please may I ask for your ideas and suggestions before I go to yamaha directly about the problem. I am slightly worried about getting ripped off.

Many thanks,

Sam.

Don"t tell the girls " they"l all want to try 4th gear ,