i just bought an 89 lt500 from a kid and im not too familiar with it. what is the sight glass window on the lower right of the cylinder for?.......thanks for any help

 

That window shows the power valve. It lets you see if the power valve is moving as the motor revs up. If you ask me it's kinda useless because most of them you can't even see through. But that is what it is. As the motor revs higher the exhaust valve should move. Hope this helps.

 

hmmmmm..........must supposedly be for fine tuning.........ok i get it.........thanks 87 racerider