Mikuni Carby Jetting

I’ve had a number of Bultacos over the years and had various success in making them reliable. One of the best mods I’ve done to any of my bikes is to fit a brand new Mikuni carby. I know some people can make the Amals and Bings run very well, but I’m not one of them. I’ve put together a table of the bikes I’ve owned and the jetting specs that work for me. Keep in mind that these may not be perfect, but they work for me.

You’ll probably have to change settings depending on the bike and the environment you ride in. The height I race in is around zero to 300 meters above sea level with temperatures from 10 to 35 degrees Celsius.

Metisse 250 M11 Pursang Mk 6 250 M103Pursang Mk 6 250 M106Metralla Mk2 250 M23Pursang Mk 8 250 M206Frontera Mk 11 370 M215
Main Jet260270270230320330
Pilot Jet303530304035
Needle JetQ-2 (159)Q-5 (159) 159-Q8Q-8(480)Q-8(480)
Jet Needle6DH46DH36FJ66FJ66PD16PD1
Slide (Throttle Valve)
Main Air Jet    RemoveRemove
Needle clip positionTopMiddleMiddleMiddleMiddleMiddle