Vm29's jetting on a '77 1075

The best way to set you air screw position is by putting a vacuum guage on the intake manifold(where the rubber cap is)Start the bike and let it warm up. turn the scerw in untill it runs crappy and look at your guage. Turn the air screw out slowly untill you reach the highest vacuum achievable. Thats where it stays. Do this on each carburator. If you end up with about 1 1/2 turns out your pilot jet is fine. If its only a 1/4 turn out, your pilot jet is too small. If it is 2 to 2 1/2 turns out you are too big. Make sense? Vacuum guages dont lie. You always want the highest reading. This shows complete combustion.

mtkawboy wrote: My street motor has a Super Bike Mike ported head, 10.25-1 pistons, 1105cc, shim on top 395 lift 260/260 cams, Dyna electronic ignition and Dyna coils plus a Kerker 4-1 with just an end plate on it, no guts inside. motor was built in 1978 or 79. Just trying to give you an idea of the combo that goes with the jetting. Correct float level is critical

Heed that advice. Fuel level is the first step in jetting

What did the carbs come off? The first thing to check is what slides are in the carbs.

For most street KZ's you want 1.5mm slide cutouts. There are a fair number of sets of 29mm smoothbores with 2.0 slides - these were used on the Suzuki GS models and larger cc KZ's.

Your pilot jet will change siginifcantly depending which slides you have.

Take a top off a carb, then on the top of the slide will be either 1.5 or 2.0.

Typical setup on a 1.5 is a 20 pilot.
Typical setup on a 2.0 is a 25 pilot.