what prop do i need to go to with for more speed?

[boaterinsd]

1) Performance issue i am trying to fix is a high engine rpm and low/ lower boat speed
2) Current prop Volvo OEM #814615-1 , aluminum 3 blade
3) Current prop diameter 15 and pitch 15 RH rotation
4) Wide open throttle RPM 5200 and speed 24 mph from a gps device boat gauge inop
5) Engine/drive 1973 Volvo Penta aq170a, volvo 270 I/O and HP 170
6) Boat is a 1973 Larson All American 18ft and weight is unknown

I feel for it going 5k plus rpm the speed should be much greater than 24 mph
I also what to do some pulling of tubes, wake boards, and or water skiers.

 

[steelespike]

Re: what prop do i need to go to with for more speed?

If its 170 hp you have a performance issue.While it does over rev a little,rated at 5,000.
I have a feeling the tach may be wrong.Reading high.Yet should be much higher with a 15" prop.I think we need to varify the tach before any further action. With the right pitch I think it should
run in the mid to high 40s at least.

 

[boaterinsd]

Re: what prop do i need to go to with for more speed?

ok, i will ck it first. thx