Can't have the battery cables connected backward if the starter worked and the engine runs. The most likely thing to be burning is the generator's output terminal. A less-than-perfect connection will result in resistance which results in heat build-up, which further degrades the connection until it really overheats. The fix for that is a replacement generator and a new terminal crimped AND soldered for a solid connection.

Answered by caradiodoc (expert)
17,272 answers provided