Whats A guy Suppose to do??

I just got off the phone with the guy at the yamaha dealership down the road, and he says he didn't see any jet kits at all for the 87-92 warriors. they used a different carb after 93, im sure theres guys on here that own pre-93 warriors and have filter/exhaust and other mods where they needed to rejet.
Whats a upshot young lad such as myself suppose to do when he hasn't even got his pipe on yet and the quad is already backfireing and crackling like crazy when i let off the gas?? advice anyone??

ummm... get a newer carb??? srry man i really cant help ya, but im shure some people on this site with warriors under 93 could help ya