Timing a Farmall M Diesel

Anonymous-0 · Sep 25, 2009

I"m having trouble getting the gas side of a MD timed. The diesel side runs fine, so I know all the engine components are timed right. However, when you try to start the tractor on gas, it will hit only 5 or 6 times in a row. Sounds like the ignition is out of time, but I have timed it according to the book numerous times with no improvement. Also, it smokes (black) a lot when trying to start, but I can find no way to adjust the carb. Does anyone have any experience with one of these tractors that might help?

jfrankhash · Sep 25, 2009

I can't help with the timing question, I have the same trouble. Howefver, I solved the "black smoke" problem by cutting off the diesel fuel under the tank when I switched back to gas before shutting down. It appears that I was getting some diesel blow through while on gas, and it remained in the cylinders when I went to start it the next time. Helps with the starting, but is still slow.

pete 23 · Sep 25, 2009

The smoke when running on gas may be due to fuel not shutting off completely. Make sure lever on pump is fully against internal stop when throttle is in shut off positon(can tell by just feeling of the lever). You could open the bleeders on all injection nozzles when starting just to see if that helps. That could tell you if fuel is being injected during start up if the smoke clears with bleeders open. Note, even a correctly adjusted pump will deliver fuel through the bleeders as there is no resistance to fuel flow when bleeder is open. There is no positive shut off in the pump, the plunger is rotated to the point where not enough pressure is developed to open the nozzle. That adjustment is done by adjusting the rack internally. Far as ignition timing, set static timing for tdc and when it is running on gas, you might get it to run better by playing with the timing, tweaking distributor back and forth for max speed, always staying with the most retarded positon possible. The other adjustments on manifold etc for gas start rarely get out of adjustment but it is possible.

Anonymous-0 · Sep 25, 2009

My MD did what yours is doing when I first got it. Took off carb bowl and cleaned it out good and checked needle and float. Also cleaned plugs and reset gap. Started and ran a lot better after I did this. Needs no choke to start. If you haven't looked inside the carb yet, I would start with that. My .02.

M Diesel · Sep 25, 2009

Providing the manifold butterflys are closing properly, MDs do not need much choke, and they flood easily due to the design. Choke should always be switched off [b:2bb6adac8c]before[/b:2bb6adac8c] the engine actually fires up. Two to four cylinders while cranking is all it needs, and then push choke in half or all the way depending on your machine. If you wait until it fires you are already behind the times. These machines load up the intake manifold easily and when the engine catches the air flow surge draws up a big wad of gas.

Haas · Sep 25, 2009

All these MDs are different. Mine requires full choke to start and then you gradually open choke as it warms. Mine always starts on the second or third turn of the starter. I do get some of the black smoke at startup, but it only lasts a few seconds. I hope you have noted when you did the timing that the rotor turns counter clockwise, opposite to the gas IH tractors. Also, if you have a magneto (most do) they are easy to get 180 degrees out of time, as the breaker cam has only two lobes with a 2 to 1 gear between the lobe and the distriubtor rotor. If you are getting blow back thru the air cleaner then you probably have the wires hooked for clockwise rotation or it is 180 degrees out.

Timing a Farmall M Diesel

Anonymous-0

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jfrankhash

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pete 23

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Anonymous-0

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M Diesel

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Haas

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