23 w/225 four stroke - Prop issue

[schooner]

Just repowered my 23 sceptre with a Johnson / Suzuki 225. Mechanic installed a 4 blade 14.5x17. with a 2.3 reduction, this is way underpropped. Numbers are 9 mph @3000 - 15mph @3500 - 19.5 mph @ 4000 - 28 mph @5000 - 31 mph @ 6000

My target was 28 mph @ 4000. Can anyone who is running a 225 four stroke on a 23 share their prop size and speed numbers so that I can see if I'm on target. Trying a 16x17 this weekend. Not sure what to expect.

Thanks

increase pitch to increase top speed and lower rpm. I would try a 19 but a 21 might be better depending on the load in the boat

[FELLOW-SHIP]

A 3 bladed prop is more efficient prop to use as well.

FellowShip

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My motto: Just for the Grins

[gss036]

I would think you should be able to get 40+ with the right prop. Your speeds VS RPM seems awfully low, but I run a 2 stroker on my 23WA and get 42/43 mph trimmed out at WOT.
http://www.rbbi.com/folders/prop/propcalc.htm This will give you a prop calculator site. Maybe that will help.

[schooner]

Tried a 15.5x19 three blade this weekend. 5,500 WOT gave 36 MPH. 4,000 gave 25 mph and 3500 gave 19 mph. Numbers looking better but still a little shy of expectation. Wondering if anyone running a four stroke 200-225-250 on a 23 can share their numbers? Thanks

[Briguy]

Check with trever hicks on this board or look up his old posts.

[ocuyler]

Schooner,

Your motor should WOT at 6000 RPM with a light load, indicating that you still need another 500 RPM or roughly 2 more inches of pitch. The 21" recommendation was a good one.