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Discussion Starter #1
So I recently bought a 816 with the Onan 16.5 twin and I cleaned the points but I still have no spark. And all safety switches are bypassed. Any ideas? I looked up a new coil but that's really pricey was hoping there were some other common problems I could try first.

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Check continuity through key switch to coil. Replace the condenser. Check (-) wire to points , connection could be grounding out before points.
 

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In addition to above, using a light tester, do you have static power at the points with the ignition in the "on" position? If so, you may want to check the points gap to be sure they are gapped at .020 when open all of the way.
 

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Discussion Starter #4
Ya there's power at the bolt the wire hooks to all the time with the key on. I did buy a new condenser to try today also. So the points may need to be gapped?

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Rotate the engine so the points are closed.
With ignition ON, manually open the points. You should get a spark each time they open.
IF you don't, disconnect the condenser & repeat. IF spark, bad condener.

The ignition side of the coil should have 12V whenever the key is on.
The points side should only have 12V when the points are open. The points are simply a switch to ground/unground the coil.
 

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How do you know which side is the ignition side? Both of the bolts on the top have power all the time with the key on......
That would mean the points aren't completing the circuit to ground.

You can use a jumper wire to the points side of the coil.
Ground it. When you "unground" it, you should get a spark if coil/condenser is good. That would confirm the points aren't completing the circuit.
 

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So the points may need to be gapped?

Yes, I would check to be sure that they are set to the correct gap. Adjusting the points will in effect adjust the timing of an engine. Too far out, and the engine won't start.

Using a .020 in feeler gauge, check the gap between the points with them at their maximum distance from each other. Their gap should be .020 in.

Just in case you don't know, slowly turn the engine flywheel while watching the points. You will see them open, and close as you turn the flywheel. When you see them just begin to move back toward each other stop turning the flywheel, and back it up just enough so that the points are again at their farthest distance from each other, then slide the feeler gauge between them. The feeler gauge should move snugly between them, but without any drag. Recheck the gap after tightening the adjustment screw.

And yes, one wire going into the points box, which is connected to one side of the points, along with the condenser wire.
 

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Discussion Starter #12
Is there an electronic ignition I can get to replace the points on the engine? I see videos on the Nova 2 electronic ignition for single cylinder engines. But sense both plugs fire at the same time wouldn't this work for the twin cylinder Onan?

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I had an the same Onan and I had the same problem. I had older spark plug wires that would pull up off the top of the plug just enough to lose contact. I was puzzling over it too and finally figured it out when i pulled the plugs to check them. It started right up since I had pushed down on the spark plug boot when I reinstalled everything. You may have already checked this but I thought I would throw this out there before you rebuilt everything
 

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Discussion Starter #14
Ya it has brand new plug wires and plugs. I have a few things I'm going to try today. But it would be nice to have an electronic ignition and not worry about the points and condenser anymore.

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Is there an electronic ignition I can get to replace the points on the engine? I see videos on the Nova 2 electronic ignition for single cylinder engines. But sense both plugs fire at the same time wouldn't this work for the twin cylinder Onan?

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Got this from a website of a place that sells them in Dayton Ohio
The NOVA Module is suitable for 2 leg and 3 leg ignition coils in single cylinder engines. This module is not recommended for use on engines equipped with battery ignition or flywheels with multiple magnets.
 

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Discussion Starter #17
Well I got the tractor running finally. It ended up being that the points where still dirty. I had cleaned them when I first got it but I guess not enough. Cleaned them really good this time and boom nice bright spark. But I have another question, I believe the tractor is a 816 but I'm not 100% sure. Can anyone tell me? IMG_20190106_143149215.jpg

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Congratulations, I'm glad you got it running. Your serial number would make your tractor a 1978. I can't help with the model. It could be an 816, but could also have an 8000 based number. Gravely went from the 800 to 8000 series somewhere around that time. Essentially the same tractors except for the seat pan, or seat pan and front grill surround though. It could possibly be an early G series too. I'm not up on the exact time frames. Posting a pic, or two would help.
 

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Discussion Starter #19
Here are some pictures of it. It didn't come with a seat pan. The previous owner said it had a cab on it and the pan was rusted to bad to keep.

IMG_20190105_123026419_HDR.jpg IMG_20190105_123037207_HDR.jpg

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The red hood tells me that is an 8000 series tractor. Gravely changed the color scheme from red with white hoods, and seat pans on the 800 series tractors to all red on the 8000 series tractors. Same tractors though. With the 16 (16.5) HP Onan twin, it would be an 8160.

Newer 8000 series tractors received the new style seat pans, and revised front grill surrounds. Your 1978 tractor still has the earlier 800 series grill surround.
 
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