Prop question...

[sheesh]

Hey all - New here. I have a 2000 1900SR with a 5.0L carb'd 220 V8 that I've had for about 3 seasons. She's been a great boat. What we're dealing with now seems to be an inability to get her up to 4400+ RPM. I can't honestly tell you if it was ever getting there. It currently is fitted with a 14.5x21p prop. I believe this was OEM size. The prop is in perfect shape, and I'm able to hit about 4100RPM at 45-46mph (according to my speedo). I can get the motor up to 4400 by trimming up further, but I don't gain any speed, I'm just pulling the prop out of the water.

I'd like to know if anyone out there owns a similar Maxum and if they're using a 17 or 19 inch prop. I'm thinking of moving to a 4 blade revolution SS prop with less aggressive pitch.

By the way - I've tuned her up, checked compression, changed plugs, wires, etc. For all intents and purposes, it is running perfectly, so I'm not sure if it is a power issue or a prop issue.

Picture of the C.P.O.T.

[shrew]

If you're able to trim up and achieve the Max RPM range of the motor without cavitating, then that's about it, theoretically. I'd use a GPS to accurately measure speed, not the boat's speedo. I'd bet you're getting a few extra MPH/KPH that isn't registering on the speedo. FWIW.