mike,
You can't see the rings from the carb side. You'll have to look from the exhaust side. Before you pull the exhaust manifold, I would check the compression. If both cylinders are very nearly the same, you probably don't have a ring problem. If you do inspect the rings, the clearance in the lands is so small that it is hard to tell if the ring is stuck or not. A trick I use is to smear a generous amount of oil on the visible portion of the rings and rock the crank up and down just enough to barely move the piston. If the rings are free, you can see the oil squeezing in and out between the rings and the land. Also check the cylinder walls for any signs of scoring or aluminum smearing. You may see what looks like two vertical score lines on the back side of the cylinder about an inch apart. Those lines are where the ring ends are located and are not usually a problem.
How about prop pitch? any changes there that would have caused the RPM drop?
Bill.
