[cadillac512]

Yes, take it apart and see what's wrong. If valve clearance is correct and valve action is steady (watch #7 valves from intake area while cranking) and the valves move freely when using a pry bar to open them, then the rings need to be looked at.

Before taking it apart, though, I'd put air pressure in #7 and see where the air goes...intake port-exh port-or crankcase. That will give you a clue. You'll have to keep the piston at tdc and valves both closed to apply the air. Shouldn't take much pressure to hear what's going on.



Terry