I have a old Trail Blazer 250 and I have been fixing it up, I got a new chain, new tires, cleaned the air filter, greased it all up, new oil, keeping the tires rotated. is there anything else i can do?

 

tranny fluid change, check primary clutch buttons, secondary clutch ramps, belt and clutch , make sure the oil pump is working and adjusted correctly, do your brakes work good?, swing arm bushings loose?, rear axle bearings and seals, clean and inspect carb and jets (note sizes of both jets for future reference) the list is endless , when i buy a new used quad i generally tear it down to the frame and put it back together checking everything, like jay lenno says restore it to 100% and then ride it to 70%. and i never have a mechanical problem on the trails

 

alright thanks for this list, i have another question, my friend suggested drilling a quater inch whole in the cap above the air filter, good idea or bad?

 

IMO bad