Original 380 air cool Rotax engine piston burn hole PTO side - rebored - first oversize - VM30-186 dual Mikuni Carbs - UNI Foam filters on each (original air box removed) - concerned about running too lean - think I should have changed main jet to more rich when using UNI filters - standard 140 main jets still in carbs - should I change jets & what number main jet will give me richer mixture - 130 or 150?

Original 380 air cool Rotax engine piston burn hole PTO side - rebored - first oversize - VM30-186 dual Mikuni Carbs - UNI Foam filters on each (original air box removed) - concerned about running too lean - think I should have changed main jet to more rich when using UNI filters - standard 140 main jets still in carbs - should I change jets & what number main jet will give me richer mixture - 130 or 150?[/b]


Bigger the number, the bigger the size of the jet, and the richer it gets.