Re: ’63 Gale 15HP 15D15B Doesn’t Have Nearly the "Oomph" it Should

[fisherman6]

You say new seals. I’m guessing those are gearcase seals which would indicate your have been into the gearcase and seen its innards. I’m thinking that rules out rust / corrosion in the gearcase.

Have you been through the carburetor? If it still has a cork float and has run ethanol gasoline, the float may be coming apart and blocking the high speed circuit in the carb. If you haven’t already I’d suggest rebuilding the carb with a new OMC kits that includes a plastic float. I always avoid ethanol in my outboards but changing to a plastic float is not a bad idea anyway.

Where are the carb needles set? Could it be that the high speed needle is set too rich and is bogging the engine out at high throttle settings under a load?

Have you pulled one plug wire at a time while it’s running to see if it is running on both cylinders? Be careful while doing this. Gloves and insulated pliers are good to keep you from getting jolted but the mag. You can check it with inline neon spark testers while running or use an inductive timing light on each plug wires to check for spark while running as well.

One other thing I can think of right now regarding this motor (the 60s Gale 15s) is they they are notorious for bad crankshaft seals, especially lower seals. Something to check before running it too much anyway.

There are a few ideas of things to check that I can think of for now. Lots of very knowledgeable people here. I’m sure there will be more ideas to come. Hope that helps get you started anyway.
-Ben

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