what should be a correct prop size

[betayv]

hello guys I have a 1995 wellcraft eclipse 232 with a 228/305 the prop that is in the boat now is a 4 blade 14-21, I have good speed but low RPM, the boat will not go over 3200 rpm, any help thanks.

 

[180shabah]

Re: what should be a correct prop size

I guess the "19" in your other thread was a typo?
Just guessing here, but big boat, small engine, 1.5 gear ratio probably left the dealer with something closer to a 17" three blade.

But we still don't know if you throttle is fully opened, boat is carrying extra water weight, etc.

Complete hwsii's worksheet.
And remember, "it has good speed" is diagnosticaly irrelevent. Use real numbers.

 

[Silvertip]

Re: what should be a correct prop size

The trailer is not still attached to the boat right????? Sorry -- couldn't resist. Not enough data. But before you even think about props, you need to verify that the engine is properly tuned and making full power. Changing props cannot compensate for a tired (as in worn out) or simply in need of a good tune up. If the bottom of the boat is fouled with marine growth that alone can cause poor performance. We need accurate wide open throttle speed and rpm numbers with what you consider an average load in order to provide prop recommendations. If you have some props to try, you might drop back to a 17P which would pick up 600 - 800 rpm. But start with the tune up stuff first. My thoughts are that a 23 footer is a fair size boat for a 305 and a 21P prop seems a bunch much for that load.

 

[betayv]

Re: what should be a correct prop size

ok guys thanks for the help the boat was carying 4 people, the trhottle is all the way to the forward position and my rpm are only 3200, and like a say before noat just been tune up.

 

[steelespike]

Re: what should be a correct prop size

You need to confirm the throttle plates in the carb arew opening all the way.
You need to get to about 4,600 assuming everything is sound you would need to drop to about a 12" pitch that is something like you might run on a 30 ft pontoon.
You either have a serious performance issue or your tach is not accurate.