1960 Onan 305 CCK Quit Running - Hmm

So my fairly-new-to-me propane-fueled 3.5kw Onan CCK was purring along nicely last week when I was test running it for fun. All of a sudden it just up and died after about 20 minutes of run time. I pulled the spark plugs, which revealed there was no spark. Where do I start looking?

First order of business was to find where the coil got its power from. I knew one source of power was through the "Elect. Start"/"Hand Start" switch on the front of the electronics enclosure, so I figured that was a good place to start.

I found that the switch got its 12 volt "Hand Start" power from the ammeter, so with my trusty Volt/Ohm meter, I started tracing where the 12 volts died. There was power at the ammeter and the "Hand Start" switch when I flicked it up. So far so good. Then I traced the wire from the switch to the top of a resistor, then out of the enclosure and disappearing down inside the cooling tins. I popped the side cover off where the coil resided, felt around a little and pulled out this broken yellow wire:

Fortunately the broken wire is an easy problem to fix. So many things were running through my mind that could have been the problem, such as the points or condenser going bad, coil giving up, or one of the components in the electronics enclosure. After pulling out the coil, I found that the wire hadn't broken at the terminal as I imagined, but had been worn through from the wire hitting the flywheel. I'm surprised the engine ran at all with the coil wire's bare lead touching the flywheel.

 I soldered the two ends of the wire together and clamped the coil back in place.

Since I had the piece of tin off, I decided to fix an issue with the spark plug wires not being routed properly by some technician in years past. In the photo below, the red arrow is pointing to where this person had bent the tin up and routed the spark plug wires out the gaping hole. Also faintly seen in the photo is a grommet just above the hole where one wire is supposed to exit from.

Below is showing the other plug wire zip-tied to the air filter tube, and the grommet it's supposed to exit from (red arrows). Tsk-tsk-tsk...

I was able to straighten out the sheet metal that had been bent but the paint on it chipped off. I figured that would happen but it's still a shame. Nice to have the plug wires back in their proper places.

And once everything was buttoned up, the generator fired off without a hitch. I let it run for ten minutes with a couple heaters giving it some load so it would get a little warm.

Here's an older photo of the generator prior to working on it: