I installed this coil yesterday, went for a drive and after 20 minutes or so it died on me again. It restarted for about 5 seconds then died again. The coil was very hot to the touch. After 45 minutes of talking to the farmer whose house I was in front of, it started right up and took me home. Is the next step to change the condenser and try again?
Here's an additional thought that just occurred to me. My generator does not work. All power is coming from the battery during operation. (I know I need to get this problem fixed) Could this be the root cause? The battery is sending a continual 12v to the coil instead of a reduced amount normally provided by the generator? But then again the internal ballast should drop it down to what is required by the distributer.
This is a dumb observation but on my 3B the coil is mounted on the block so it's bound to get hot isn't it? How hot is too hot?
OK, there is a lot to address here. The generator actually puts out more voltage then the battery does. If it did not, it would not charge the battery. You will not hurt the ignition system by running it on just battery voltage. Thus, the lack of a good generator is not the "root cause" of your issues. Now if the generator was putting out 24 volts, that would be a problem.
The coil you linked to does not need an external resister, so you are not over-voltaging the coil. Unless you leave the key on without the engine running, it should not get excessively hot. If you do that for more then a minute, all bets are off. That can burn out both the points & the coil. If left long enough, you can also take out the condenser that way.
What do you mean by "the coil was very hot to the touch"? If you were to touched it, would you be worried about 2nd degree burns? If so, that is too hot. It can be 210 degrees F & be OK, but much more then that could be a problem. If it was hotter then a steaming cup of coffee, it is an issue.
Should we assUme that you did not check the heat of the condenser when it quit? That would have helped with the diagnosis.
The coil being mounted to the engine block will cause it to run hotter then if it were mounted to the body away from the exhaust. OTOH, The engineers would not mount the coil to the engine block if it were an issue. I have had countless engines with the coil mounted to the block go over 300,000 miles with no coil issues. That is not a problem. Now if it were mounted to the exhaust manifold...
IMHO, the next step is to replace the condenser with a name brand one & drive the same route. Take the old condenser with you, just in case the new one is worse then the old one. Buy quality condensers. No ADA-Omix! No Asian crap. Made in Japan should be OK. Anything else from that area is suspect, at best. Echlin is a good brand. I buy mine from NAPA.
Note: If the issue was vapor lock, it would not have started right up. The carburetor would have been empty of fuel & a considerable amount of cranking would be needed to refill the float bowl with fuel.
IHTH, Cpt Logger.
PS. If you take the battery in to get tested, make sure it is fully charged first. A battery with a low charge will fail the test every time. I do not see a battery issue here.