H #64 combine won't start when hot

The place where I volunteer has a 1942 IH H and a 1952 model 64 combine with a similar four cyl. IH engine. Both have mags and normally start and run fine, but if the engine is shut-off or dies while hot, it will not restart for many minutes (usually an hour or more) until the unit has cooled down. I have been told it is a coil problem, I have also been told it is a fuel evaporation problem. When I checked there appeared to be spark. How can I check/cure this condition? I appreciate your help.

My Father and I had a 64 combine in the early 1960"s. It was a good machine when the engine ran. Ours had the 4 cyl. cub engine with a ring gear but no starter. We installed a starter and ran a HEAVEY gauage wire from the battery on the Farmall 400 to power the starter. The ground was the frame of the combine to the frame of the tractor. This helped a bunch!!!! Now if I remenber right isn"t the gas tank on top of the engine? I don"t remenber(sp.?) gasoline boiling in the gas tank and spitting out the gas cap like it did one hot fall when we had the mounted corn picker on the 400. (That was different to say the least!!). So what would happen if you moved the gas tank away from the engine? (By the way it didn"t matter what the paint color was or the engine brand(Wisc. and other engines were just as tempermental as the brand names when mounted on implements!) I never gave the gas tank location any thought until now as we traded the 64 on a PTO driven model 76 combine. Solved the engine problem but exposed some different problems that we solved by trading for a SP model 303. One other way to solve the engine problem would be to find a PTO drive. It was a option for the 64. Armand

Back on the '50s & early '60s when I was growing up we had two IH # 62 combines with the 4 cyl Continental (Cub) engines. These engine were notorious for being hard to start when hot. My uncle always said the reason he had two was so he would have one to use while the other's engine was cooling off enough to restart. I know once they were started they were never shut off till night came, even let them run while we went in to dinner. Only time the engine was shutoff during the day was if it was killed from a slug, which wasn't all that uncommon. Even when greasing or working on the combine the engines were left running

Thanks Armand and soybeanjoe for the comments. The PTO is not an option since most of the farming is done with horses. The gas tank is above the engine but there is still gas in the carb when this happens. I heard that it was a common problem and you both confirmed that. We have been leaving it run, but as you said a plug, unloader gearbox/belt problem, or such requires a shut-down. Buying a working second unit may be difficult. I will just keep struggling with them for now. Thanks guys!

We also had a 64 combine in the 50s with the cub engine. It too was hard to start when hot. It had the ring gear so my dad put a starter on it. With the starter it would start even when hot as the starter would turn it faster than you could crank it. My suggestion would be to get a cub starter and large 6 volt battery, assuming it has the ring gear. We didn't have a generator on it as we only needed to start it a few times a day. Al

My cousin had a 52R with the Continental power unit. He used this back in the 60's and had the same problem. He used to pull the coil and put it in the freezer for 10 - 15 minutes and then it would start back up. As cheap as coils were, Cousin Walt was cheaper.

Thanks Al. Both the H and the combine have starters, but this does not seem to help.

When it won't start pull off a plug wire and see what the fire to your plug looks like. You could try another condenser to see if that helps.
Hal

We had a 50T baler with a motor that was the same way. We always had another tractor with a belt pulley and a long heavy V-belt handy and started it with that. Worked great. Tried everything with the motor, but would just not start hot.

One other thought on your problem. We had an H that the mag went bad on so I converted it to battery ignition. I used the points in the mag and connected them to an external 6-volt automotive coil and condenser. Worked good for years. Or you could just get a battery ignition unit from another IH tractor and install it.

I would try putting reflective foil insulation between the carb and the block. I would also put foam pipe insulation over the fuel line. If it has spark, and does not run it is either getting too much fuel, or none. Either can be caused by heat.
Jim