M will not start

Dudley Brand · Dec 31, 2011

Just bought a 39' M today. Pretty good shape for its age. Has had a lot of work done to it. Also has brand new rubber all the around.Went to start it and could only get it to run for short bursts , spraying gas in the carb.Removed carb. to check gov. connection and is ok.Carb looked nice looking done from top. Good gas flow , and mixture screws look new.Also someone has turned them recently. Need to know the base adjustments for the carb. or any other ideas. Has good oil press. and compression.12 v.conv.
Thanks,
Dudley

Luther · Dec 31, 2011

Check air intake . Also oilbath for nest.

glennster · Dec 31, 2011

main jet 3 and 1/2 turns out. idle mix, 1 and 1/2 to two turns out.

pete 23 · Dec 31, 2011

If it will run by spraying gasoline into intake of carb like you indicate I would just screw the main jet out a few turns to try. Once you get it running you reset it. There is no 100 per cent accurate setting for a dead engine, it is a starting point. Get her warmed up, run wide open , turn it in until starts to lean out, back out to running good and give it another half turn or so. Idle screw, set for best idle. Can be anywhere from half turn out to couple of turns depending on carb and engine conditions. And, the idle screw is air, so the farther out on that one the leaner on a M.

El Toro · Dec 31, 2011

Disconnect the gas line at the carburetor and remove the tube fitting from the carb and look for a screen behind that fitting that may be plugged. If that looks clean hold your hand over the throat of the carb while a helper makes an attempt to start the engine. If there's very little suction means you have low intake manifold vacuum. Could be a leaking manifold gasket or isn't tightened enough. Hal

El Toro · Jan 1, 2012

Will the engine make an attempt to start during cranking without spraying gas into the carburetor? If it does you may have a defective ballast resistor. Hal

Tom Fleming · Jan 1, 2012

First off, welcome to the forum. In addition to what has already been said, here are some other thoughts.

When you say you have good fuel flow, how did you test that? the absolute best way to test is to remove the fuel bowl drain plug and see how the flow is.

From the symptoms you describe, it sure sounds like fuel supply. It could be the screen at the IN side of the carb, which has been mentioned. It also could be the float hanging up in the CLOSED or near closed position.

Keep us updated on what you find.

Dudley Brand · Jan 3, 2012

Swapped carb. from a running M and it runs now, but has bad governor.
Again thanks for the help.
D.B.

mkirsch · Jan 3, 2012

(quoted from post at 06:28:57 01/03/12) Swapped carb. from a running M and it runs now, but has bad governor.
Again thanks for the help.
D.B.

Bad governor, or did you miss the notch in the governor/carb linkage? That's a common mistake even for experienced wrenchers.

Like, did you pull the cover plate on the governor and find pieces or missing springs?

Dudley Brand · Jan 3, 2012

Did double check for connection from gov. tube, It was O.K. Not broken or junk inside but a lot of slop with all the moving parts. It wants to race and too much play in throttle. Unhooked gov. near breather and could force it to idle down.

M will not start

Dudley Brand

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Luther

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glennster

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pete 23

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El Toro

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El Toro

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Tom Fleming

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Dudley Brand

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mkirsch

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Dudley Brand

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