i have a '98 w/ air mods and 50shot wet nitro...i ran it the other night and it instantly backfired twice...i parked it and turned it off...tried to turn it back on and the rpms went up, down, up, and then it stalled...that happens every time i try and start it now and the only way it doesn't stallout is if i give it some gas...even then it'll stall when going from reverse to first...but back to the story...i replaced my spark plugs w/ stock ngk's (they were stock before too), and it still is having problems...oh, and one more thing -i can't go over 4000 rpms no matter what...?!?...i talked to a person at a shop who has nitro, and he said that its either a blown gasket, valve, or bent rod and that i should get a compression test done on the chambers to see if its ok and then go from there...any other suggestions? if blew a piston, what then, titanum?? anyone know of any websites?...thanks, i'll post this in the nitro section too