farmall m engine spins backward

sven · Oct 11, 2011

After my farmall m has run a while and the engine is warm, it tends to spin in reverse for a few seconds upon shutting it down. Is this a product of the timing being too far advanced?

mkirsch · Oct 11, 2011

When you shut the engine down, the timing has nothing to do with it.

The usual cause of backfiring and "dieseling" (i.e. continuing to run after the ignition has been turned off) is carbon buildup.

Revredneck · Oct 11, 2011

Don't know for sure on a tractor, but the leading cause of a car dieseling is the idle speed set too fast. By the way, the engine doesn't run backwards when it diesels, the carbon build up in the combustion chambers is so hot, it self-ignites, like a diesel.
Good Luck and God Bless

Allan in NE · Oct 11, 2011

Yeah,

I've seen 'em do that; kind of smoky mess ain't it? :>)

Make sure it is idleing slow when ya kill it.

Oh, and for what it's worth, after you shut off the ignition, there is no timing. Just a hot hunk of metal.

Allan

JMOR · Oct 11, 2011

(quoted from post at 09:37:21 10/11/11) After my farmall m has run a while and the engine is warm, it tends to spin in reverse for a few seconds upon shutting it down. Is this a product of the timing being too far advanced?

ust as you hit kill switch, let clutch out with it in gear & brake on...problem solved.

Absent Minded Farmer · Oct 11, 2011

Give the tractor a minute or so to cool down before you shut it off. I usually let it idle at about a third-throttle for that long & hit the off button. I learned that trick with my Model A (Ford) to keep it from backfiring & breaching the muffler. I do remember something about carbon build-up, too. Just can't put my finger on what it is at the moment.

Mike

mkirsch · Oct 11, 2011

A red-hot chunk of carbon in the cylinder head will ignite fresh air-fuel mixture when the compression gets to a certain level.

Super-H-Mike · Oct 11, 2011

The only way for timing to be involved is if it is way retarded when running and makes the engine run too hot. After killing the switch you have no more spark,the fuel is self igniting like a diesel engine. Caused by poor octane fuel,high compression, engine too hot, carbon buildup, even the wrong spark plugs if the tips get red hot while running. My SM does this too. And sometimes it sure does seem like it is turning backwards like you said ! I just shut it down in high gear with clutch depressed, and then let it out slowly to stop the engine. Sometimes just letting it idle a couple minutes after working it will help, because the engine cools off then . Idle speed too high will do it too, as it lets the engine have fuel with which to diesel.

sven · Oct 11, 2011

I am pretty sure it spins backwards. It pushes exhaust out the air intake, and if I leave it in a foward gear while pusing in the clutch when I shut it off, I can let the clutch out slightly and it will drive backward.

rustyfarmall · Oct 11, 2011

(quoted from post at 08:00:38 10/11/11) I am pretty sure it spins backwards. It pushes exhaust out the air intake, and if I leave it in a foward gear while pusing in the clutch when I shut it off, I can let the clutch out slightly and it will drive backward.

I've witnessed first hand the same thing but on a John Deere 4010 and 3020, both of them gas, not diesel. Both tractors were worked hard any time they were running, so I really don't think it has anything to do with carbon build up. The only answer to prevent it was to let the tractors set and idle for a few minutes before shutting them off.

old · Oct 11, 2011

That is called dieseling which is caused by hot spots in the engine like carbon build up. I would run some ATF in your gas for a while. Use a qt to 5 gal. of gas to help clean the carbon out. Yes you can also do that with MMO but ATF is a lot cheaper and will do the same thing

Janicholson · Oct 11, 2011

Slow Idle speed settings, and this brakes and letting out the clutch in 4th or 5th is correct. Jim

pete 23 · Oct 11, 2011

That is the reason mfgrs went to the electric shut off solenoid on carburetors as even when everything was done correctly some engines still had a tendency to diesel. I thought that Minneapolis Moline actually had a pretty good idea on their carburetors as they went to a coil spring stop instead of a solid pin. You set low idle gently against that spring and when you shut throttle off against that spring pressure it completely closed the throttle plate and they shut right down.

Allan in NE · Oct 11, 2011

When there's smoke coming out of the air pre-cleaner, they are turning backwards.

Allan

rustyfarmall · Oct 11, 2011

(quoted from post at 12:27:07 10/11/11) When there's smoke coming out of the air pre-cleaner, they are turning backwards.

Allan

Exactly!!!

Allan from PA · Oct 12, 2011

I have a 1945 AV that would do that and gave me fits. Somebody on the forum here said to try Hi-test gas in it and I did. Has worked perfect ever since. Allan.

farmall m engine spins backward

Our Phone System is Down!

Please use the Contact us Form

We are working to resolve the issue ASAP! Thanks for your patience!

sven

Member

mkirsch

Well-known Member

Revredneck

Member

Allan in NE

Well-known Member

JMOR

Well-known Member

Absent Minded Farmer

Well-known Member

mkirsch

Well-known Member

Super-H-Mike

Member

sven

Member

rustyfarmall

Well-known Member

old

Well-known Member

Janicholson

Well-known Member

pete 23

Well-known Member

Allan in NE

Well-known Member

rustyfarmall

Well-known Member

Allan from PA

Member

Similar threads