Tillotson air balanced 1928-34 carb

[LAV]

This is a new carb and can’t start. Good fuel getting to the inlet of carb, and the gas flows thru valve great but wont start unless I use starter fluid, then runs and stops. New carb, wouldn’t think I’d have to set the float, but out of ideas. Timing is good and fuel is good. Help. Thanks

[Wick]

Air leak. Gasket good between carb and manifold? Engine is pulling air instead of fuel.
That's why the starter fluid works.

[Purdy Swoft]

It does sound like what Wick says . I did have a similar problem with a Tillotson model X . .The air adjust screw had to be just right . Usually one and one half turns on the air adjust screw is normal . I had to fiddle with the air adjust screw to find the sweet spot .

[LAV]

I have a good gasket and have filed down smooth the the manifold and the carb is new. To eliminate the air leak issue. I don’t think it is an air leak. How do I check float level in Tillotson carb?

[Ernie Vitucci]

Good afternoon...your air leak could well be between the intake manifold and the block...it has happened to me. Ernie in Arizona

[LAV]

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Ok, I’ll check that out. Thanks. Any word on how to check float?

[Bruce of MN]

This has a tip, not sure where I got it:

[LAV]

Thanks so much. This is a real help. I am trying to make sure I eliminate any chance of air leaks fore I do anything else.

[Ruth]

A friend installed a "new" air-balanced Zenith he got from one of the vendors. We couldn't figure out why it would not run unless the GAV was open 2+ turns and was real hard to start. Even with the GAV open that far, it ran real lean. Plugs were white.

Turns out this "new, made in USA" carb had excessive clearance in the throttle shaft, thus sucking in air. Might want to check your throttle shaft.

[LAV]

Changed gaskets to check for air leaks; did not help.
I slightly adjusted float and now it will start and run (well) for a short time and dies. I have adjusted the GAV (1 full turn) and the air/gas screw (3/4 turn) to the settings on the instruction sheet. Anybody have ideas on how to proceed, without guessing to find the proper settings? Send the carb back? If so are Zenith’s any better? I want to get this one working. Thanks.

[wmws]

Have you tried taking the full line off and letting at least a pint of gas run out. I'm thinking gas cap vent issue. Or possibly the feral on the gas line is letting the gas line enter too far into the carb thereby slowing fuel supply. I'm not sure if that is relevant on a Tilly.

[LAV]

Gas into carb is good. Thanks though

[Patrick L.]

Was there a problem using the old carb ?

If you choke the heck out of it does the carb throat get wet ?



Ooops, somehow I missed #10. I doubt the problem is float level but its easy to check and adjust. It should set level which should be 1". Adjusting is by bending the float arm carefully.
Tilly's like more GAV opening than Zenith's. Try starting at 1 turn. Idle mix should be as Purdy says, 1.5 turns to start out before adjusting.

[LAV]

Thanks