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m37 spark plug fouling

Posted: Sun Oct 16, 2011 6:55 pm
by wc16
Cant seem to keep spark plugs from fouling (carbon). New plugs, almost new rebuild on engine. Plugs are available from OReilly or NAPA or military vendors but only in one heat range. Appreciate some input thanks

Re: m37 spark plug fouling

Posted: Sun Oct 16, 2011 7:15 pm
by mozark
How recent a rebuild? Wet fouling or cold fouling?

MM

Re: m37 spark plug fouling

Posted: Sun Oct 16, 2011 10:26 pm
by cuz
You have a hotter military plug in the 2245 autolite. Are you running civvy plugs? If you are what number are you running?

Is the carbon fouling after short duration runs or runs of an hour or more?

Is the engine heating up to normal operating temps during your runs? What temps are you seeing?

Re: m37 spark plug fouling

Posted: Mon Oct 17, 2011 6:42 pm
by ZGjethro
I was having constant wet fouling, and I had gas in my oil. I had 120-125 psi (I think, it was a few years ago) in all cylinders so my rings were good. Finally the truck would not start and I pulled the carb. I had gas puddles in the manifold. I would check your carb for a too rich condition if you are wet fouling. I sent my carb to M-series rebuild and it has been running great ever since. I do not know what was the issue.

I also had a faulty pressure regulator which may have been the flooding cause.