Re: Carburetor float levels, Zenith B and Tillotson

Posted by H. L. Chauvin on April 07, 1998 at 00:08:57

In Reply to: Carburetor float levels, Zenith B and Tillotson
posted by Larry Jenkins on April 06, 1998 at 14:14:46

: The B engine ... runs very rich and little power even with the dash control off, and will even backfire occasionally.The timing appears to be correct, as it starts right now and idles well. I have been told that perhaps an incorrect float level may be the problem
: Is 5/8" correct for a Zenith B carb, and what should the level be for a Tillotson?Any other thoughts on what may be causing a very rich running engine?
: Many thanks..
: Larry Jenkins
Hi Larry,Humble opinion: If timing is correct, note that choke rods rub fire walls in A cars with B engines with B intakes;maybe, choke is binding & partialy closed causing rich mixture.2nd, if possible, to save time, borrow a friend's good running carb to try in your A--if friends carb allow yours to run well, your carb needs work; if friend's carb does not improve your A's performance, carb is not problem. If your carb is problem, check sticking float, dirty float valve, and possibly leaking/sinking float which can cause rich mixture.Also, page 3, "Patent Cures", Vol 39, Issue 3, Sep/Oct 1994 "Restorer" echoes what was done by former mechanics of the era, i.e., "always set float such that the float is parallel to the upper body when the float valve is seated and closed--applies to A's & B's."If carb float sticks to side, leaks & sinks, or fails to float upwards to close float valve when float is parallel to upper body, mixture will be too rich, (usually evidenced by black smoke exiting exhaust when reving the engine), hence poor performance.
Best wishes, Henry

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