Farmall M w/ a miss

Anonymous-0 · Feb 9, 2009

One of my M's has a miss and I cant seem to locate the problem.....Its the #2 cylinder, I've swapped the plug, wire, cap, and rotor and it doesn't change. I even swapped the wire and plug with another one on the tractor and nothing changed. Theres no spark coming out. and by the way it's a distributor. Not sure what else it can be, it has ran fine before. the distributor shaft is fine, I checked that. what are your thoughts?

old · Feb 9, 2009

Your saying no spark from #2 plug right?? About the only thing that could cause that is a bad lobe on the distributor shaft and the points are not opening for #2

Janicholson · Feb 9, 2009

If you unhook the wire from the plug, and put a different plug on the wire, ground the different plug, then crank it up and run it, does that plug fire?
If it does, I would do a compression check on that cylinder. If it does not, one of the things you changes was not good!
It could be a stuck valve. or a burnt valve, or a broken valve spring, or other issue. JimN

Brownie 450 · Feb 9, 2009

Try taking a compression test on all the cylinders. I'll bet #2 is low on compression or has other problems---valve hanging up--burned valve--could even be an intake gasket leak on #2 side of the #1 &2 intake gasket. If you remove the valve cover, have a good look around---could be something like a broken rocker arm or a pushrod jumped out of its' socket.

Anonymous-0 · Feb 9, 2009

It's not a compression issue....it doesn't have spark, I pulled the plug and grounded it against the block and.....no spark....the lobe on the distributor looks just like the other 3.....something just isn't adding up....I will have to go over everything when i get a chance again, I ran outta daylight tonight.

Anonymous-0 · Feb 9, 2009

How about a bad spot on the distributor shaft/bushing that allows wobble when #2 should be firing, same thing as bad lobe.

old · Feb 9, 2009

Yep that would do it also but again if he looked at it he could see the point not opening on #2 so either one could be it

El Toro · Feb 10, 2009

See if the point gap .020" is the same on all lobes when set on the high point of the cam lobe on the distributor. Move the cam lobe in the distributor to see if there's any slop from wear.
Hal

Brownie 450 · Feb 10, 2009

Since you have swapped out plugs--wire--the only thing left is the #2 plug wire terminal on the distributor cap is getting grounded out inside of the cap---but how?? Is the bakelite dust shield under the cap clean & in good shape?? There surely can't be a grounding issue with the spark plug threading into the head?? Are you checking the spark with a different plug held up against the block [ground]?? I had a brand new Champion plug that was grounded internally & couldn't get a spark through it. I'd stick a small screwdriver in the #2 hole on the distributor cap & hold on tight to see how much voltage --if any-- you are getting, while it is running. There has to be a reason that the #2 isn't getting spark.

Brownie 450 · Feb 12, 2009

Another thought--- maybe the distributor is 1 tooth off & the rotor is not perfectly aligned with the distributor cap terminals--so that the spark has to jump a long gap to the cap terminals. And---if #2 terminal is just a little bit too far for the spark to jump---no fire to #2.

Farmall M w/ a miss

Anonymous-0

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old

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Janicholson

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Brownie 450

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Anonymous-0

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Anonymous-0

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old

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El Toro

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Brownie 450

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Brownie 450

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