Raw Fuel Out Exhaust

Possible causes:

Valve seal
Valve guide
Valve seat
Valve
Piston compression ring

Anyone else with other possibilities?

I am assuming that the spark plug is firing and the plug wire is functioning.

In reference to my previous post, I had the same indications as you have and so I pulled the valve cover and verified the torque on the rocker arm shaft, that the pushrods were in their rocker arms properly, and that the seals were still installed properly.
Then I pulled the head. I saw a small scoring on the cylinder wall and pulled the piston. I found the compression ring had a small broken area. I also had the head checked at a machine shop to make sure the seals, guides, and valves were ok.

Good luck with what you find. I hope it is easy and inexpensive to fix.

Art