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Martin

My Onan doesn't have spark.......

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Hey folks hope you can help. I'm pulling my hair out. I have a D160 that was retrofitted with a P220 previous to me purchasing it. I used it all this spring and summer but left it unused this fall for 6 to 8 weeks until the other day. It always started right up in the past. This time I couldn't get it to start it tried a couple times but then it would just roll over and over. I pulled the plugs and they were wet and full of soot. I cleaned them up and tried again with no luck. So I dug around and found all the service manual for trouble shooting the P220 Onan. The coil has the appropriate resistance of around 3 ohm primary from + to -  and 19K ohms between the secondaries. The control module goes from battery voltage to about 1 volt once per full revolution. I replaced the plugs with brand new and still no spark. I also hot wired the + side of coil from the battery with no change. 

 

 I'm out of ideas.and the winter snows are approaching fast.. 

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Posted (edited)

I fixed it inspite you helpful folks around here....it was the coil in spite of it testing as it should...

Edited by NOSValves

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what ohm reading should you get on the module? Does it change as you rotate the engine past TDC. Also if its a Hall effect does it have voltage rather then a permamnt magnet type sensor?

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Gents. I am still getting no spark from my coil. Is there any ohm reading check I can make to test the coil trigger mechanism? If I apply a meter to the trigger wires red and black that are connected to the coil psosts I get a very high K ohm reading and no change if I rotate the engine. If I apply voltage to the pos of the coil and rotate my engine with voltmeter on pos and engine ground still nothing. HELP!!

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If it is the trigger is there any easy way to get the flywheel off?? Do I need to time it before I remove it and do i mark it? What puller can I buy to get it off??? What size are the 4 bolts on the front face of the flywheel I think 1/2" head. Help Again!!

 

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You measure the control modules voltage at the positive terminal of the choke. As the flywheel rotates the voltage should go from battery voltage (12 or 13 VDC) to about 1 VDC as you rotate the flywheel. If you search the internet for a service manual for your onan it has instructions for testing the ignition system. But even those instructions are not fool proof. My coil tested fine but ended up being bad. But it had an obvious crack across the top. 

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3 hours ago, leachy said:

If it is the trigger is there any easy way to get the flywheel off?? Do I need to time it before I remove it and do i mark it? What puller can I buy to get it off??? What size are the 4 bolts on the front face of the flywheel I think 1/2" head. Help Again!!

 

 

 

What model tractor are you working on? 520?

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