Farmall M - What to do

Anonymous-0 · Sep 14, 2009

Farmall M that is smoking so bad I have to do something. Lots of blue smoke; to illustrate I had a spark plug loose and oil was coming out of the spark plug hole. Other than the smoke the engine ran well until the other day when the number 3 piston quit firing due to a fouled plug. Repaired the plug and soon fouled again. What to do? I have the head off and pistons out and there is nothing obvious wrong. Cylinders measure 3 7/8 at the top. Tractor is used 4 hours per month as a hobby. Do I get an engine kit or simply replace rings (oversize) and hone the cylinders? Money is a factor.

rustyfarmall · Sep 14, 2009

What do the cylinders measure when you drop down about 1/8" from the top?

JT · Sep 14, 2009

While you had the haed off,did you check valves and valve guides, in my opinion, if the rings were worn so bad that it was blowing oil past them, would not have enough compression to run.

Anonymous-0 · Sep 14, 2009

I cannot measure below the ridge. I will borrow a bore gauge for measuring tomorrow from the auto parts store. Sleeve top is 3.854". Piston bottom is 3.870 and piston top is 3.853. Sleeves 2 and 3 have visual 'water line' marks but I cannot feel the marks with my finger. Sleeves 1 and 3 look good with no marks. All 4 pistons look good too. Randy

SDE · Sep 14, 2009

Remove a ring from the piston. Put the ring back in the cylinder. Measure the end gap on the ring. How sharp are the edges of the ring.

How often are you adding oil? You have it apart because you know you need to do something about it. You can do it right, or you can do it cheap.

I had the crank ground on mine and put new rings in it. For a little more money, I could have gotten sleeves and pistons.
Steve

Janicholson · Sep 14, 2009

If the tops of the pistons are washed to clean around the edges with oil, it is time. The Kit is about 500 (shop it here, and with others, Rusty Farmall Etc.) The top of the piston where the rings are should be much smaller than the measurement given. The wear in the cylinder is greatest where the top ring stops. Put a ring in that spot, (I'll bet the end gap is greater than .040", not good)
Do it as best you can afford. JimN

charles todd · Sep 14, 2009

If it still runs strong (enough for your needs) and you are tight on funds, I'd but a case of oil... It is cheaper. Personally, I think you are due for pistons, rings, sleeves, and a head job at the least. Also, if you are that deep, check the oil pump, cam and crank as well as associated bearings... While you are at it, a full gasket kit... Don't want leaks.

CT

gene bender · Sep 15, 2009

Since the head is already off i would get new rings and like you said hone the walls.

Farmall M - What to do

Anonymous-0

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rustyfarmall

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JT

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Anonymous-0

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SDE

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Janicholson

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charles todd

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gene bender

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