hi guys,
I have a 1997 formula III long track snowmobile, but the triple blue up and I put a 583 rave motor in. The motor was bored .60 over but no other mods were done to the motor, Im only getting up to about 130 kilometers an hour at top end, is this normal? also when im in the deep powder for a while and the track is spinning alot (full throttle) the motor bogs down and I have to run it on packed trail to clear the plugs, they seem to be fouling when the throttle is held wide open for an extended period of time. Im thinking the carbs need tuned but what am i looking for?

drop the main jets down 1 size (ten numerical sizes, for example from 330's to 320's)

Something isn't jiving, my 583 does 100mph on speedo all day.