I found this forum through Google and was blown away at the knowledge I saw here. I found another reversion thread on here and did find some information useful but his problem was a little different than mine.

I have a 79 Ironhead and I'm fairly certain I'm dealing with some sort of reversion problem. I've done every test I possibly can in regards to ignition, and fuel and I know that neither of these are the cause of my problem. There is good compression on both cylinders.

I can't get the bike at suggested idle rpm at all. The rear cylinder is firing but is very weak. When the bike is idling I can pull the rear plug wire and not a lot changes. When the front wire is removed the bike falls on its face and dies. The front cylinder is running super rich and the rear seams to show little to no color on the plug.

At idle the carb spits a little fuel here and there and when the bike is shut off it appears to have steam coming out of the carb. I pulled the intake manifold and carb off and both intake runners are soaked in fuel.

I know cam timing can very well be an issue but I pulled the cam cover off and the cam timing was spot on. The rear exhaust pipe sounds almost like a under water boat exhaust or something. Also, When I unplug the rear cylinder while idling and leave it unplugged for a few seconds, When I plug it back in I can get a few strong fires out of that cylinder until it goes back to the way it was.

So with all this being said I'm fairly certain I'm having a really bad reversion problem that's keeping the rear cylinder from running right. If its not cam timing what else can it be? I'm runnin out of ideas and I really want to start riding before the weather gets bad.

There's only one carb.  When H-D first went to fuel injection, the engines didn't sound 'right'.  A fair amount of research (I think documented in an SAE paper) revealed that, because of the dynamics of gas flow in the shared intake manifold, five of every twelve cycles produce a misfire in a carbureted Harley that's running perfectly.  So the fuelie computer had to be reprogrammed to simulate misfires in order to get the sound right.

Yours is not running right, and the symptoms you've reported point to an ignition problem or a valve problem.  Expose the valve springs, crank it through a cycle with a wrench, and check the static timing of both cylinders and the valve/(Needle Valves) operation.

If your bike still has the stock waste fire "dual fire" ignition, that could likely be the problem. If the coil has 2 low voltage connections, it's dual fire, 3 terminals (or dual coils) for single fire. Just about any cam change requires a "single fire" ignition be installed, it will also improve low rpm running even on an unmodified engine so the investment won't be wasted. These systems aren't cheap, so people often remove them prior to selling the bike, to increase their bottom line a little.

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