Front Sprocket?

The oil leak would be the seal. You're blaster is 16 years old so it's probably due. I'm not positive but I'm pretty sure the front sprocket should have a little bit of play.
 
NO, there shoudl be a little bit of play, not much at all but if you see how the sprocket goes on you will know what i mean, it slides on those the groves which allows a tiny bit of play otherwise youd have a biotch of a time putting it on, and then the little metal peice that the bolts go into holds the sprocket on the groves so it doesnt come off.
 
yeah, a little play is common and the seal behind the sprocket is bad, its like 3$ from yamaha its usually the first one to go
 
NO, there shoudl be a little bit of play, not much at all but if you see how the sprocket goes on you will know what i mean, it slides on those the groves which allows a tiny bit of play otherwise youd have a biotch of a time putting it on, and then the little metal peice that the bolts go into holds the sprocket on the groves so it doesnt come off.

Couldnt have siad it better my self lol