Muzzeloader, put that cylender at top dead center on the compression stroke. Then apply air to the sparkplug hole. listien for air comming out of carb , tailpipe, and crankcase- crankcase will have some no mater what, but if you are not getting any compression it should be alot. other places should have very little or none. this could be a stuck valve. BUT YOU SAY IT RUNS SMOOTH? HMMMMM. CHECK YOUR COMPRESSION GUAGE. could be bad valve. not keeping pressure.
