Basic H carb questions

JDnTN · Aug 31, 2009

What is the "starting point" number of turns out for the air adjustment screw on a rebuilt carb? I assume that "loosening" the screw allows more air not gas. Is that correct?
Thanks,
JD

CNKS · Aug 31, 2009

Turning the the main mixture IN leans the mixture. Turning the idle mixture screw in richens the idle mixture. Initial settings are 2.5-3 turns out for main, 1-1.5 out for idle mixture. Start the engine, let it get to operating temperature, turn screw in until is stumbles, out until smooth plus 1/4-1/2 turn. Turn idle mixture screw in or out until the engine idles smoothly. Pull throttle back rapidly, engine should accelerate smoothly. Repeat adjustments until engine accelerates smoothly. If it refuses, clean carb in real carb cleaner and put in a kit. Some people turn the main screw out until engine smokes, then back in -- this is not necessary.

JDnTN · Aug 31, 2009

Which screw is which?
Thanks.
JD

old · Aug 31, 2009

Main jet is the lowest one on the carb and the idle is up close to the manifold

Wayne in MN · Aug 31, 2009

Idle rpm is highest; idle air mixture screw is just below and high speed mixture is on the bottom.

Basic H carb questions

JDnTN

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CNKS

Well-known Member

JDnTN

Member

old

Well-known Member

Wayne in MN

Well-known Member

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