my ten year olds blaster had a fmf fatty and fmf silencer powercore 2. i looked and it has a 260 main jet, no airbox, and k&n airfilter. it runs like a scalded dog, fast as hell. anyway we mostly trail ride with familly so i put the stock exhauset back on just to quiet the thing down. my question is can i just leave everything else alone or should i change the main jet or put the airbox back on. it seems to run just fine and plenty fast enough for my 10 year old.
