Re: Starting over! What bike with a 4 stroke?
That motor just needs a little TLC, more than likely you got one that has an improperly balanced crankshaft, which is why it feels like you're gonna disintegrate at 30. You probably Are.
The best thing I ever did was balance and stuff my crank. And it's not even 'properly' balanced, it still vibrates some, but not like it used to. I remember my hands going numb on longer rides from the vibes.
See if there's a dirt bike performance shot or other motorcycle shop in your area that can balance it for you, best if you disassemble the motor and give them just the crank.
It'll be a lot cheaper than the 4 stroke. =P