David,

Cleaning the jet properly will require disassembly of the carburetor and the use of Gumout Carburetor Cleaner or something like it.

Make sure that you clean out the bowl real well there's probably some sediment in there that gets stirred up as the boat moves.

Also, make sure you have a top quality fuel filter/water separater (like Rayco) before the fuel pump and a extra-fine polishing filter between the fuel pump and carburetor.

For the polishing filter use:
NAPA (Gold) 3032 (351B3K).

If you have a copper tube fuel line between the pump and carburetor you'll have to replace it with flexible fuel line. (I think Don Moyer sells a fuel polishing kit with everything you need, check his website at www.moyermarine.com).

I hope this helps.

Good Luck,
Steve.