Steiner 420 not reliably starting

Ray Plank · Dec 7, 2016

I have an older Steiner 420 with an Onan Performer 20XSL motor that has begun to intermittently refuse to start. I have a +12 volt bulb attached to clip leads that I attach to the - terminal of the battery and the + terminal of the coil, and get a nice bright 12 volt light. I hook up the spark tester to the spark plug wire, and don't get a spark when I crank the engine. I even hook the spark tester directly to the coil to see if the plug wire is bad. Still no spark. Ok, I bought a new coil, carefully installed it last night, and got the same symptoms. The only time I get a spark on the tester is when I turn the ignition key to OFF. So far, it has started right up the first time I try it, but if I shut it off and try to start again, it may or may not start.
It cranks, so none of the safety switches are open, I'm getting voltage at the + terminal of the coil, I have a new coil. Where do I go from here ?
Thanks for your help.
Ray

Pipestone Kid · Dec 12, 2016

Ray Plank said:
I have an older Steiner 420 with an Onan Performer 20XSL motor that has begun to intermittently refuse to start. I have a +12 volt bulb attached to clip leads that I attach to the - terminal of the battery and the + terminal of the coil, and get a nice bright 12 volt light. I hook up the spark tester to the spark plug wire, and don't get a spark when I crank the engine. I even hook the spark tester directly to the coil to see if the plug wire is bad. Still no spark. Ok, I bought a new coil, carefully installed it last night, and got the same symptoms. The only time I get a spark on the tester is when I turn the ignition key to OFF. So far, it has started right up the first time I try it, but if I shut it off and try to start again, it may or may not start.
It cranks, so none of the safety switches are open, I'm getting voltage at the + terminal of the coil, I have a new coil. Where do I go from here ?
Thanks for your help.
Ray

Is it old enough to have a condenser? If so, that would be my guess.

Stimw · Dec 12, 2016

The coil needs a "trigger" whether it is points or electronic module.
You need to look at what ever triggers the spark for problems.
For instance, if points are stuck closed or not opening you will get a spark when energizing the coil.

Ray Plank · Dec 13, 2016

It does have a condenser, attached to the + side of the coil, and I have not replaced it yet. That may be my next move.
I am getting a "Trigger". I've attached my test light to the - side of the coil, and it turns on/off/on/off when it's cranking. ( but still no spark ! )
Later when I tried it again, it fired right up. ???!!!

Stimw · Dec 13, 2016

The condenser at the coil is probably only for radio interference.

Ray Plank · Feb 20, 2017

Problem Resolved. It finally broke hard enough for me to find the problem. There is a sensor behind the flywheel that senses the magnets turning, and pulses one side of the coil, creating the spark voltage. This finally went all the way bad, giving no pulses on the test light on that side of the coil. It was a little more involved than I wanted to go ( Removing the motor, pulling the flywheel, etc.. ) so I had a guy do it for me. It's running like a champ now !