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Onan B46M ticking and shorting plug wire

1897 Views 1 Reply 2 Participants Last post by  Hydriv
Got my new-to-me 648 running finally after some hydraulic leak fixes and new muffler fab. Just installed new points/wires/plugs/oil to try to get it running like new again. Engine has a reported 630 hours and was running OK before the new parts. The plugs are correct, points set to spec, and wires installed same as originals. I used parts from vendor Garys Place.

Problem is that the plug wire molded ends seem to be shorting against the engine block. I know the wires are the economy version, but in all my years working on small engines with all kinds of crappy 20 year old parts I have never seen plug wire ends arcing and shorting to the block - no matter what their condition. I got quite a shock when I tried to wiggle the plug wire ends to see if they were loose. I cant find any cracks in the ends of the wires and they are correctly coupled to the spark plugs.

Going back to the original 30 year old onan wires fixes the visible arcing, but I can still hear a lot of ticking and one cylinder is cooler than the other, so I likely have an ignition and/or valve problem.

I am ordering the gaskets to check the valve clearance, and then plan on compression testing and leakage testing. What about wire end arcing? Would the coil or poor grounding somewhere be causing this?
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If you go back to the wires that were on it and the problem no longer exists, then I'd say that the wires Gary sold you are crap and you should talk to him about them. People say he's a decent guy and will do the right thing. After all, most Sellers don't run tests on everything they market. They rely upon customer feedback to sort out problem items and ..............perhaps.......problem suppliers.
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