Mariner 50 power loss

[sylvan16]

My 1984 Mariner 50 has lost power. It seems to start easily and run as smoothly as ever, but it does not rev as high as it used to and won't put my 16' aluminum semi-vee up on plane. It used to do this occasionally when cold, and would suddenly "open up" after about 5 or 10 minutes. Now it does it all the time. This happened rather suddenly. The engine does not run hot, no smoke, the fuel lines and fittings are in good shape and do not appear to be leaking anywhere between the tank and carbs. Fuel filter is not blocked. This model has dual carbs with, I believe, integral fuel pumps. Before I try to take these things off, anyplace else I might look to solve the problem?

 

[JB]

Re: Mariner 50 power loss

Ahoy, Sylvan.<br /><br />Welcome aboard.<br /><br />I'm not very familiar with your engine, but I can suggest some generic initial troubleshooting tactics.<br /><br />Get a Manual. Without it you may be more hinderance than help to your engine.<br /><br />Check each spark plug wire for a hot blue 1/2" spark to the block.<br /><br />With the engine at idle, disable each spark plug in turn. If rpm drops that cylinder is making power. If there is no drop in rpm that is a dead cylinder.<br /><br />If you have good spark to a dead cylinder, overhaul that carb.<br /><br />Good luck.