I have a 1987 yamaha warrior 350 and it runs great. The only thing is that the chain is definitely too loose. How do i determine the right amount of slack it's supposed to have. And i know it's too loose because i was riding the other day and it just popped right off and got wedged in the axle.

 

it helps to have another person with you when you tighten it up. get them to sit on it as you tighten it. it helps if they are about the same size as you. if you don't have someone to help, a few bags of concrete on the seat will work also. I tighten mine up until I have between 1/2 to 3/4 inch of slack.

 

I would tighten it before it comes off and wraps around the front sprocket.If it does this it might break the case of your motor and you dont want that.

 

yep and you dont want that, mine had the side of the cases broke enough to where it leaked oil everywhere and it sucked, luckily my dads an experienced welder and he repaired it, but thats a pretty common thing for warriors to break those off so id adust asap b4 u ride again its fairly simple