1990 Mercury 70 hp motor loosing compression in one cylinder

Larson70

Seaman
Joined
Jul 9, 2012
Messages
67
Jumped into the boat market by purchasing a project. Bought a 1972 Larson Shark with a 70 hp Mercury Motor. Boat is in mint shape but the motor is loosing compression in one cylinder. I plan on pressure testing it today to figure out what cylinder has the problem. How would everyone go about the next step after figuring out the problematic cylinder. Also my motor apparently does not have a head gasket so that isn't the problem (says a boat mechanic). Any advice, steps, or ideas. Thanks, Mike.
 
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