Coil getting really hot without running

parluskq · Jun 2, 2016

I am working on a buddies 1986 john deere 317 with a kohler kt17.. He said it has not ran in years. I cleaned the points and re-gaped them and still couldn't get any spark so i bypassed the seat switch, still nothing. So I ran a wire from the positive side of the coil to the battery and got it running. I noticed that the coil gets hot even if i am not running it... Is there some type of resistor that I have bypassed?

jenkinsph · Jun 2, 2016

It used to be that when cranking the coil was fed with full voltage available and when returned to the run position it placed a resistor in series with the coil to lower the voltage. This helped as cranking with the old batteries suffered a significant voltage drop (maybe 9 or 10 volts available). Don't know what the more modern small engines use today but a resistor may still be used for this.

Leejohn · Jun 2, 2016

Points were closed when you shut it down letting the coil go to ground. Points might be burned up now.

parluskq · Jun 2, 2016

Leejohn said:
Points were closed when you shut it down letting the coil go to ground. Points might be burned up now.

I was laying in bed last night and this exact same thought came into my head.... I didn't leave it hooked up long. I went down this morning and I am still getting good fire so I think I will be okay. I may trace all the wires down and see what the original problem is, but the wiring in this old thing is far from stock.

Clint S · Jun 2, 2016

Yes it will get hot with the coil ''hotwired'' and the points closed. Either fix the wiring or put a new switch in. Sometimes it is easier just to start from scratch on the wiring if it is that. bad

parluskq · Jun 2, 2016

Clint S said:
Yes it will get hot with the coil ''hotwired'' and the points closed. Either fix the wiring or put a new switch in. Sometimes it is easier just to start from scratch on the wiring if it is that. bad

If it were mine I would rewire the whole thing... the wire isn't bad its just who ever rewired the thing only had two colors and used way too much wire. I am going to put the coil wire on a switch for now just to make sure its going to run and operate okay, then I will see what my buddy wants to do as far as the wiring goes.