Hesitation at wot

[89retta]

Hi guys I just bought a 04 Caravelle 187 with the 4.3 225hp Volvo. This is my first boat with an inboard. At full throttle the motor cuts in and out till I back it off some.Tach is showing 5700rpms till I back it off. The prop is a 17 pitch SS and has a good ding in it. I called the guy I bought it from and he said it was the rev limiter. Does this sound right? Thanks for any help.

 

[captmello]

It could be the limiter, you should not be hitting 5700 RPMs. do you have a spare prop to try? a higher pitch, 21 would be better. Did the guy say why he was running such a small pitch?

 

[89retta]

No I don't have a spare prop. The guy who sold used it for wake boarding. I was thinking of moving up in pitch as I don't like the damage on the prop. By moving up 4 pitches it should drop my rpms to around 4800. Also do you think the hub could be slipping in the prop. Dash speed was only showing about 40mph. Thanks for the quick reply and any help.

 

[captmello]

No I don't have a spare prop. The guy who sold used it for wake boarding. I was thinking of moving up in pitch as I don't like the damage on the prop. By moving up 4 pitches it should drop my rpms to around 4800. Also do you think the hub could be slipping in the prop. Dash speed was only showing about 40mph. Thanks for the quick reply and any help.

No I don't think the hub would slip and still push you at 40mph.

Save that prop for a spare and pick up a 21p.

 

[89retta]

Got hold of a 19 pitch prop to try. Fixed the problem still hits the limiter if I trim up to much.. Showing about 5300 on the tach. Going to try a 4 blade 20 pitch and see how it does.

 

[89retta]

I went and bought a 5 blade ss 21 pitch. Still turning 5200 at wot and hits the limiter if I trim up. Speed is about 43mph. Could something be slipping in the leg or elsewhere? This is my first inboard so don't know where to start. Thanks for any help.

 

[dypcdiver]

If you trim up the blades will be surface piercing and probably causing cavitation. The racers have props designed to be surface piercing without the cavitation, not usually an off the shelf item and costing many$$$$.