farmall m IDing parts/model


New member
I am in the process of ltrying to fix a plug fouling problem mostly cyl 2,3,4...
It turns out it is non standard.. Pistons are 4 inch M&W. but flat topped..!!
It should e a gas only tractor (1950) I need to get new rings and gaskets.
That is not a big concern right now.. but I would like to know engine model ( I think its C248) and why most of the stuff I have found in the last couple of hours indicates M&W have either cratered/recessed or ridged pistons.
pictures if it works

edit: crank is 5.25 stroke..not the 5.75 m+w change.


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New member
so far,, c248 seems correct for engine. also rings for 4 inch M&W pistons is 2C7997 set... It seems that is correct for all versions of 4 inch M&W
pistons. Pistons are marked 11F3 inside skirt. Flat topped.
top two rings are 3/32 next is 1/8. oil ring is 1/4
Head in machine shop to swap valve guides. and remove one broken exhaust stud.
I will keep in touch if any further concerns arise.
Don..... north west wisconsin..