For motor to smoke like that something has to be way wrong. Rings upside down, possibly broken.

It does almost look as tho someone dumped diesel in the gas.. Front plug wet says rings tho..

 

Ok, so, I'll take the motor out, redo the rings (being sure to note the positioning of the rings) and while at it do the valves. Should I buy all new valves and springs, or just the seals? Springs would probably wear out with use, but valves?

Thanks again for the guidance and lessons.

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A compression and leak down test before a tear down would be advisable. If the rear cylinder is holding compression and not leaking down, leave it alone and focus on the front. The leak down test will tell if valves, rings or guide seals are leaking and you can replace accordingly.

If you don't have, can't borrow, don't want to buy the compression and leak down testing equipment. Pull the top end, no need to "take the motor out". Find a shop or tech that knows Harleys and have the cylinder bores checked in torque plates and pistons measured to confirm, or not, that piston to cylinder fitment is within service limits and the cylinders have a true bore. If not, and cylinders can be bored to 3.938", buy new pistons/rings, gapped and install properly, replace the valve guide seals and re-install the top end. Break in properly and problem should be solved.

You are going to find something awry when you tear down the top end.

 

Just ordered the compression tester. I appreciate your help. I really wish I could go spend a year in AZ and get formal training on Harley's, but not really an option right now. So, it's trial by attempt and occasional failure... Still enjoy it though!

 

Compression test alone may not tell much. Leak down test will give more information. Regardless it needs to come apart. Did it smoke from soon after first start or only after replacing leaking head gaskets. What head gaskets did you use?

 

You got oil blowing past some place into the combustion chamber and and you want to leak it or comp test? Maybe I should have leaked my FXDX when it broke a rod..

 

The OP says the issue is limited to the front cylinder. Testing before tear down might reveal that the rear cylinder is OK. For sure the front cylinder has to come down but what would it hurt to test and maybe find that the rear cylinder doesn't need to come down?

 

A compression or leak test can tell you if the cylinder is bad but it doesn't necessarily tell you it's good.

 

Come on Max. At least the test results provides more information about rear cylinder condition than the OP has now and he can make the decision to pull it down or not.

 

Haha! There's no winning with max. You should know that by now.