Coil issue?

[Lt.Mike]

Last couple times I’ve worked my A I’ve had problems with a restart when hot. It starts up fine when cold but after about 30 minutes of running it may refuse to start. It’s gets spark from the mag to the cap but it’s an orange spark. It has to sit a long time before it wants to start again then when it does it’s like it never had an issue. The tractor has a 12 volt alternator but that just involves the starter and lights.
I’m thinking the magnetos coil is failing but I just hate to fix things by swapping parts till I hit it. Is there a reliable way to test the coil against a multimeter? Either way I’m going to do a full tuneup on it.
Mike

[John *.?-!.* cub owner]

Most likely it is the coil as you are suspecting, however, the condenser can cause that too. Even ith good test equipment it is difficult to tell the difference. Check the points first, if any question at all, change them and the condenser. That will leave the coil as the next suspect.

[Lt.Mike]

Generally the whole tune up kit, points, condenser, cap, wires, and plugs cost about the same a just the price for the mag coil.
I’ll do that first before I buy the coil.