I got a 1991 trail boss 250 4x4 today, so what should I do to keep up with maintaining it? oil, filters? its in good condition, got it for 1500, and what are some upgrades I could get for a 91 that would be good?

 

those were actually pretty good bikes...pretty mean little 2 stroke for a ute bike..you can do just about anything the guys are doing to trailblazers but dont expect it to be a sport bike cause no matter what you do its gonna drive like a tank

 

and its starting to backfire a couple times when coasting downhills, is this niormal? oh and he said theres a exhaust leak or something?what to do about that?

 

The exhaust leak will cause backfiring. You will have to find out exactly where it is leaking for us to tell you how to fix it.

 

the leak os right behind the metal panel on the right side, where the two pieces connect with small springs, exhaust come out where the two connect, there is no hole.