502 for spectra jet boat?

Edit your question- need to know your current WOT rpms, and the jet model.

----------------

So, 4 days later, and the 2 vital bits of info are still missing. This makes it impossible to make any recommendations for increased performance. If your engine is currently making maximum recommended rpms (4600-5000), increasing engine hp and rpm will shorten the lifespan of your engine significantly. In this case, modifications to the intake, as suggested by Mike, or hull mods such as weight removal, hull blueprinting, lift pads, etc. are the only practical methods of increasing speed. If your engine is running at lower than the maximum rpms, increasing fuel intake may give you an increase in hp, but to determine this, you will need to have your engine dyno tested, and an exhaust gas analysis done.

As a final note, I have rebuilt many BB GM engines over the years, and have had more success with 6-pack (3- 2 barrels) carburetion than with dual 4 barrels. Not only is this more economical at cruising speeds, but has a better response from mid to high rpm transition.

Spectra Jet Boat

I don't work on a lot of jets,but one of the best modifications for speed is the intake grate/ride plate.No matter how much horsepower you have,you have to get water to the pump/impeller, and the intake grate is where it starts.I don't think that more horsepower is your answer.