[McGillicuddy]

Just one suckers opinion but, if you can't get max target RPM, at WOT with a load -swap the prop. If you're slow out of the hole, swap the prop. Wrong prop for this hull. Viper is a speed prop. Too much long sweeping blade and probably too much rake. Get a stern-lifting design, 14 x 15 or so. There are many options - but what you have sounds suspect.

You have a top notch motor, don't cheat yourself by settling for the wrong prop. I'd take it back to the dealer and let him know you'd like to try some other options. Like the old SST 13-3/4 x 15....I'd be willing to bet you get better performance from a $100 Merc Aluminum Black Max than the Viper. I'd move away from the BRP props altogether. You can do much better. PowerTechs OST3R15 is like the old SST and a respected stern-lifter. New SST has double cup but it might be too much. You should be able to get nearly 40 mph with a fresh etec 115 on a 20 with the right prop and set-up.

Check your motor height, too...it will perform best with the anti-cav plate at least an inch above the keel.