I have a 99 Bayou 300 4x4...it has ran very good for years, 2 yrs back the choke cable froze, and I never replaced it. I would always choke it by putting my hand over the opening of the carb. Anyways, lately it been hard to start so I have been shooting it with Starting fluid to get it to start. It has lately been backfiring- it seems in the crank case, or so it sounds. the bike runs good, it just does it when it is sitting still. It also seem to run a little hotter. I just replaced the choke cable, and it starts great, but revs a little high. My dad said it could be the timing.could this be true? if so how can I check, and were is it? or is it some thing else? Help!