| Wasted Spark Design [message #134979] |
Sun, 17 July 2011 22:27  |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma:
|
Senior Member |
|
|
I have worked an many wasted spark ignitions over the years mostly on 2 cylinder motorcycles and a few Onans. I thought I remembered how the coil was designed but now I'm doubting what I thought I knew. I know it is just a basic transformer with a single primary winding but it is the secondary I'm concerned about. I thought the secondary was one winding with a center tap to ground. I have a used replacement Onan coil in my hand and I'm not reading anything between the spark plug terminals (secondary) and ground (the case). I also looked up the wiring diagram and it does not show any center tap. If this is true then the spark plugs must fire in series using the engine ground as the cross connection between the plugs. If they do fire in series then my diagnostic procedure was flawed because I had both of them disconnected when I was trouble shooting this Onan problem.
Does anyone out there know how this coil is wired internally? Yes, I have read the diagnostic procedure in the Onan manual.
The other problem I have on this replacement coil is the secondary only measures 14.5k ohms. The book says it should be 40K ohms. I do not have to original here right now to measure it.
Ken B.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
