Carb recommendations for 1948 FL

[kurly]

Hi All, I'm just putting the the finishing touches on a 1948 FL that's been hanging around in the back of the shop for the last 20 years. I have what I believe to be the correct carb a M-35 TP. I also have a couple M-74Bs, a M-75, and a M-74A. Palmer states M-35TP is correct, and M-75 is optional for my application. Just a rider but trying to be mostly correct (No Judging, some aftermarket including 12Volt, primary belt). Is their any performance issues between a M-35 "1-1/8" venturi" compared to a M-75 "1-5/16' venturi"? or the M-74A? Fixed Jet? I will eventually hang a side hack on the bike, and I realize gearing is the key to side car happiness. I am not a racer, just enjoying the back roads, No Freeways. What are your experiences?

Thanks, Curly

[T. Cotten]

Keep the 1 1/8" venturi for a hack, Curly!

Could you please post pics of the M74A, especially the stamp?

(I collect pics, thanks..)

...Cotten

[kurly]

I'm sorry, My mistake Tom I have a M-45A not a M-74A. Can't read my scribbling notes. I see that they don't list a M-74A.

Thank Curly

[T. Cotten]

I had my hopes up, Curly,..

That you had yet another L&L enigma;
As a student of carbs, it is the exceptions to the rule that excite me.

The M-45 and M-45A rarely crossed my benches, but I recorded a unique high speed needle seat, which is an enigma to me.

Before I spoil it with a pic, can you please inspect yours? And please report the fixed jet number?

(Two more are scheduled to cross my benches next week, for no other reason than inspection, as Liberty still has a moratorium on new carb accounts: Only manifold and float requests can be accepted,.. thanks everybody.)

....Cotten
PS: Yes, the consensus seems to be that the M35TP is "correct" for '48s, but it would really be nice to nail down when the M35T was used,.. or the fabled M35F and M35S,.. and lately an M35P was reported!

[kurly]

Tom,
My M-45 A has one fixed jet. A #57 drill (0.043) fits all the way through, and a #56 drill (0.046) fits partially through. I don't know if this is the correct way to measure a fixed jet but was the only way I could think of determining the size. The other side just had a solid plug, Is this the norm?

Curly

[T. Cotten]

That's how I'd do it, Curly!

My chart isn't handy for the #19 jet, but its bore would indeed be stepped.

Here is what I recorded for an M-45 A HS needle seat:

M45ASEAT.jpg

Another L&L enigma.

.....Cotten
PS: The fellow with two cores he wanted inspected was a no-show.