632 Dies when hot

[hp0617]

This past weekend we were moving some brush and firewood around with my 632 (Ford 4 cylinder gas engine) and when it got warmed up real good it just died. It showed no signs of anything electrical working at all - no warning lights were on and nothing responded to turning the key. I let it set for a few minutes and it started right back up and acted normal for 2 - 3 minutes then it would die again. I did this routine probably 10 times until we got our woodpile taken care of. Any ideas where I should start looking for a heat related problem that would just shut everything down until it cools off a little?

 

[OldMachinist]

The first thing I'd check is the battery ground cable on both ends. When it shuts down see if ether end feels warm or use a test light from the positive post to a bare spot on the engine and see if it lights. If it does it again after cleaning grounds use a old screwdriver to jump the large and small terminals on the starter and see if it turns. That will tell you that your getting voltage to the starter and that the problem is in the wiring to the fuses or start panel. But I'm still betting on a bad ground.

 

[Tazza]

The first thing I'd check is the battery ground cable on both ends. When it shuts down see if ether end feels warm or use a test light from the positive post to a bare spot on the engine and see if it lights. If it does it again after cleaning grounds use a old screwdriver to jump the large and small terminals on the starter and see if it turns. That will tell you that your getting voltage to the starter and that the problem is in the wiring to the fuses or start panel. But I'm still betting on a bad ground.

I don't know if this engine has a temperature sender to shut down if it got too hot, i know some of the old air cooled ones did. When the cooling fins cloged up with dirt it would get hot and shut down to prevent it over heating and being damaged.
Could it be a bad coil? the heat doing something to it making it not create a spark?

 

[jerry]

I don't know if this engine has a temperature sender to shut down if it got too hot, i know some of the old air cooled ones did. When the cooling fins cloged up with dirt it would get hot and shut down to prevent it over heating and being damaged.
Could it be a bad coil? the heat doing something to it making it not create a spark?

Had a 632 that did that and I went through the carb, fuel pump, coil and finally found that the ignition points had closed up so there was hardly any gap. Only thing I can think of is the engine heat caused them to close completely till it cooled a bit. regapped them and that was the end of the problem.

 

[hp0617]

Had a 632 that did that and I went through the carb, fuel pump, coil and finally found that the ignition points had closed up so there was hardly any gap. Only thing I can think of is the engine heat caused them to close completely till it cooled a bit. regapped them and that was the end of the problem.

Thanks for the ideas guys. I have some starting places now to check and double check.
I'll give you a little history about my 632 now. It has very few hours on it since I had the head reworked and we also put a new coil, points, plugs, wires, etc, and, rebuilt the carb. It's possible that we were using it more and certainly harder this past Saturday than it had been used since we put it back together. When it first died Saturday with all the electrical dead the first thing I checked was the battery cables and the ground cable was loose. I tightened it up and it fired right back up. The battery and both cables are also new in the last few weeks.
Thanks again for the ideas and I'll start going back over things and double checking to see if something else has maybe come loose or needs adjusting.