OMC 2bbl carb help

[Fast Fred]

lookin for some help on OMC carb jets, main jets- what is the deference between a "C" jet and a "D" jet.


ever see a set of OMC 2BBL's with jetted nozzles?

howed ya's get the nozzles out?, thinkin i'll make a small puller

Thanks
FF

[Skoontz]

Fred:

I have, in my tool box, available through Snap-On, a jet removing tool for OMC carbs. It is basically a glorified screw driver with a 3/16 diameter shank that the tap to connect with is only as wide as the driver shank.

The OMC engineers would know for sure, but I beleive at one point the jets were cast tight into the aluminum and no longer removable.

Hope this helps

[Bill Gohr]

The difference between the jets is the direction of fuel flow through them, the D flows front to back, the C back to front, and yes it does matter. The nozzles you are talking about would be the air nozzle in the front? That comes out with a cork screw type easy out by hand, we had made tools for them which were an easy out with a tee handle welded on it, the main nozzle had a tool which clamped around the outside of it and twisted out, those half the time would get destroyed coming out. They are not cast in, they are pressed in. The front air nozzles come out easy.

Jet tool, way back when Snap-on did make the jet removing tool, it was very expensive, so we had someone else make them.

[Fast Fred]

The difference between the jets is the direction of fuel flow through them, the D flows front to back, the C back to front, and yes it does matter.

awesome.

the main fuel Nozzle, sounds like best get new ones then try to pull the old ones out, sounds,?,


ever see a 2BBl set with a jet in the bottom of the Main Fuel Nozzle?
thanks
FF
ya i run a Stanley modded by FF to get the jets in and out, 3bucks

[Fast Fred]

yes, seems thare is some different main nozzles sizes, .130 thou' and a .150 thou', i need 6 .130 thou' Nozzles, whos got some? comeon i know yous got some

[NERSTROM]

Fred,
The jet in the bottom of the main nozzle was an attempt to lean the carb out at higher RPM's to better follow the power curve. As RPM went up so did fuel flow to the point the engine would start to 4-stroke, the jet in the nozzle in combination with the main jet had the effect of leaning the fuel curve as power went past peak. EFI systems eliminated this problem. We found it easier to jet for reqular gas than with AvGas, the higher specific gravity of the regular fuel tended to flaten the curve as well. Generally, to get enough octane we would use a 50/50 mix. All this was before gas was made from corn!

[Fast Fred]

thanks, gas hear gets shipped in, in a 55gal drum, "Corn free" Red 110, i'll check
the gravity of it, i don't like to mix with pump pee, seems like a good way to win a DQ, you had Leaded i bet.


41c was the main with a 38 in the bottom of the nozzels, she is washin on the top side of the curve with out a a jet in the nozzel. exhaust temp slows down,
that i bet is why, pullin to 8000rpms, exhaust temp is 1025deg. f
thanks
FF