What happened to my coil ?

[TimmyV]

'61 Pan with 12 volt system. Running Accell super coil ( 3 ohms ). Wiring to/ from coil checks out for continuity, have 12 volts running to coil from ignition switch, good wiring from coil to distributor. Bike had been running fine, although it is still a project in the works & has not been ridden regularly. Battery has 12.7 volts with motor off.

Last night while checking something out, I accidently left the ignition switch on for about a half hour. Finally noticed that switch was on & coil was HOT. VERY HOT. Let things cool down & checked the coil out this morning by removing a spark plug from head, reinserted it into plug wire & grounded plug to motor. Turned ignition on & opened points, no fire at plug so I assume coil is fried.

Saw in knowledge base that if I test with ohmeter across the 2 small terminals on coil & do not have continuity then coil is toast. Right now there is no continuity there so I assume coil is a goner. Correct assumption ?

Since ignition was on for extended period of time without opening points to release energy in coil, is this what fried my coil, or is this indicative of another problem somewhere ?

[FlatHeadSix]

Timmy
Your guess is correct, if you have no continuity across the primary side of the coil its toast. Leaving the ignition on for an extended time probably cooked the tiny wire used in winding the primary side of the coil.

I'm not a real big fan of anything ACCELL is marketing these days, they seem to have a high failure rate even if you don't abuse them by leaving the ignition switch turned on. Try a different coil and see what happens.

mike

[TimmyV]

Thanks for the reply Mike. Okay, so this is another hunnerd dollar lesson for me. Now that I am looking to replace coil ( presently 3 ohm coil), is there an advantage to possibly replacing it with a 4.7 ohm coil or is the 3 ohm the way to go ?

[Bosheff]

Why not use a Genuine H-D -65 coil?....bosheff