So, a few days ago in a snowstorm ( errr, flurry ) I hit something in my driveway, a frost heaved rock that tripped the plow springs . The Normally stout running 448 went from running great, to a pair of gerbils running around in the motor. I thought at first the carb took a shot, but after diagnosing that, nope. Right cylinder just not running right, no power to speak of, exhaust smelled bad, ran funky after going over a bump or two.,..
So Sunday afternoon I spent going through things a bit, and just keep in mind I had this Onan running pretty darn well this fall. What I did Sunday:
Set points to .021", they were worn down to .016,. cleaned 'em with the dollar bill trick.
Adjusted R side valves to .005 , and .013.
Adjusted L side valves, actually exhast only, to .013". I did not have the time to do the intake, as the intake manifold must be taken off to do this unless one has a special 3 knuckled wrench I think. But it was at .007 " anyways, so close enough anyways.
Put some new plugs in the thing, Autolite 437's, and ran it around for a bit even though it was still sounding doggy and had little power. Left head was running 235 F, and Right head at 110 F, hmmmmm
Popped the heads, and de-carboned them, nothing serious, just a light coating of carbon.
Put it all back together, and went back out to load test it. Still a dog, less so, but still a dog.Pulled her up to the shop, let her cool down and scratched my beard a moment......
This thing fires both plugs at the same time , Right???? Swap the plug wires fool....
The dog of a cylinder came alive, and the other one ( lefty ) went weak.
Out came the coil, onto the bench and I got 4.3 Ohms between the + and - side, and 34K Ohms between the spark plug terminals. That, my frienss, is terminal.