Help, valves

When I get on the gas real hard I hear a vibrating in the front of my quad, and one of my friends said it might be the valves, how do I know?

[MichaelS693]

this might sound stupid but i aint bein like sarcastic but look at your heat shield it might be the bolts rattleing out mine does it every so often and it is my bolts:D :) :D :)

[Leo]

my frame skid loosened up just a tiny bit on my once, made a heck of a racket when the motor was wound up tight.. :)

whatever you do make sure to check the simple stuff before going to crazy!

Leo

[Castor-426ex]

could be a loose headpipe

[gojk]

Could just simple be the plastics. I know my front plastics have a vibrating sound to them that sounds bad when wound up but it isn't anything to worry about. Just plastic on plastic vibration.

[EricB]

have someone listen close to your engine, if there is a clattering from the top end it might be. but these engines winde pretty tight, you would have to run the piss out of it to float the valves hehe.

[RideRed400StYlE]

make sure you spark plug is tight, I heard a rattle coming from the motor, and my spark plug was ready to fall out. the washer on the plug was what was makin all the noise