M-35 Main Jet

[billpedalino]

I rebuilt and installed an M-35 carburetor on my 1947 FL a couple of months ago. I generally install a No. 18 main jet in my Linkert carbs. to ensure a rich mixture at high speed operation. I have not run the bike yet and won't start it until the spring.

After installing the unit on the bike, I looked at Palmer's data charts and noticed that the M-35 didn't have a main jet installed. Now I'm thinking that if these carburetors were meant to draw their high speed volume through the open hole with no jet at all, will I be running too lean with the No. 18 fixed jet, or can the jet remain, as it is standard on in the later M-36, M-36B, M-61B and M-74 units?

Thanks...

[T. Cotten]

Bill!

Fuel is metered by the HS needle in its seat on an M35, not an 'open' hole.
The galleries should be plugged.

Your HS needle should have a 45º point. (Later civilian carburetors that used fixed jets had a 22º point, with a much smaller seat.)
With an extra fuel source, your needle's control would be defeated.

....Cotten
PS: These things are sure forgiving, ain't they!

[billpedalino]

Thank you Tom - that's good information...

I'll re-install the 2nd plug.

Bill!

Fuel is metered by the HS needle in its seat on an M35, not an 'open' hole.
The galleries should be plugged.

Your HS needle should have a 45º point. (Later civilian carburetors that used fixed jets had a 22º point, with a much smaller seat.)
With an extra fuel source, your needle's control would be defeated.

....Cotten
PS: These things are sure forgiving, ain't they!

[knuckleheadtim]

Also, the M-74B uses an entirely different main nozzle which supplies more air to better emulsify the fuel. Therefore, a fixed main jet was added to balance out the fuel.