I had to replace the carb on my mf 50, but don't know how to adjust it. It is idling fast, runs rough, and smells rich. There's an adjustment about 10 o'clock from the fuel intake, and one on the right side of the carb. It has a big knurl knob on it. Can you tell me what the two are? thanks!
- Thread starter NebrBob
- Start date
I"m guessing it"s a Marvel-Schebler carb. The big knob is the power jet and it should be backed out ~1-1/4 turns. The small adjustment on the updraft part of the carb is the Idle air adjustment(unscrewing it leans the mixture) It should be screwed out ~3/4 turn. These are starting points. Start the engine and let it warm up. Adjust the mainjet so the you can accelerate the engine smoothly from low rpm to high rpm. the idle jet should be adjusted to give you the lowest idle speed and then the speed adjustment screw should be used to set your idle speed 400-500 rpm.
Bob M
Well-known Member
Jerry - Correction to your last sentence: The idle jet should be adjusted to give the FASTEST idle speed. Then reduce the idle to 400 - 500 RPM using the idle speed screw (throttle shaft stop screw).
Often the smoothest idle can be achieved by repeating the idle jet/idle speed adjustment sequence 2 or 3 times.
Often the smoothest idle can be achieved by repeating the idle jet/idle speed adjustment sequence 2 or 3 times.
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