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cncman08

allis 720 timing

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cncman08

I replaced the points in my 720 set the points to .020 and timed it to the mark on the front of the engine with a timing light. When doing this I notice that the timing light gives different readings depending on which plug wire it is connected to about a 1/4" difference. Is this a indication of a bad coil or condensor? I was going replace the condensor also when I did the points but the one I got from Napa had to short of a lead. The reason I ask is that under load over 2/3 throttle it loses power and starts to die until I back down on the throttle.

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HerbP

I also haven't been able to get mine back to working well after I replaced the points/condensor... I wish I'd left well enough alone. It took forever to till this weekend because the tractor would bog down far too easily requiring me to turn off the PTO and wait for it to sputter back to life, raise the tiller, turn it back on, gently lower it again, and move another couple feet before it bogged down again. I don't have a timing light though.

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cncman08

I am planing on replacing the condenser, rebuilding the carb and plug wires. If that does not fix it I am going to do the head gaskets and look into the coil. This whole problem started because I realized my governor was not working. I adjusted the throttle cable correctly and put the correct spring on. Now the governor works and I am finding many other things that are in need of repair.

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ka9bxg

I had the same problem and it started on the last big snow we had. Tryed a few things and nothing worked. Called a freind that works on onans and was told to replace the condensor.It helped alot but what made the big difference was to open up the point gap some more. Works much better but still need to put a new condensor in it. Open up the point gap a little might work for you also. Bob

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cncman08

Bob I replaced the condenser last night and it did not help much. I think it is a fuel problem. I am going to try rebuild the carb next week.

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michics

I to have been through the whole tuneup thing on these Onans. Wires, coil, plugs, carburetor. Before you spend the money on a rebuild kit from Onan ( about $80 ) you may want to consider just replacing the carb. If your carb is bad. Mine was bad and I tried to get by cheap by rebuilding. Still wound up replacing it.Try this if you need a carb. Has adjustments on the top.http://www.autotestsys.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=ATS&Product_Code=ZEN13793

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cncman08

I may consider the new carb even though mine is not in bad shape. I like the adjustment on the top. Is it it a direct fit? Is it the same size?

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michics

Yes, it is a direct replacement. My motor was running bad and I replaced everything else before the carb. Should have done it first.

As soon as I started it and adjusted the screws a little the motor calmed down and purred like new. Well worth the money.

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