I know it's not a car but this is the only place I can think of to ask about re-jetting snowmobile carbs. I just picked up a '79 SRX with a rotax 503 and dual carbs. I want more power out of it, the carbs have already been replaced and the main jets are 120's. What size jets would you guys suggest I use? I've got dual tuned pipes, and i think the carbs are mikuni 38mm. I know that they are Mikuni just not sure what size exactly. Anyway, What size do you suggest?