Only 4500 -4800 RPMS- 90 HP Johnson on 20'SF

[Texascoastalfish]

I took her out and ran the 13.75 X 17, and got 4900 RPMS at WOT and 31 MPH. Looking at the clearance between the bottom of Cav plate and the tips of the prop we are looking at 1/4" ,I also have another 13.25 X 17, and a bid on a 13.75 X 15. I'm 1" above keel with motor now. I'll try the smaller diameter 17 P first, then the 15 P 13.75. trying to get above 5200. Im 400 short now. I haven't checked compression yet, I am running with a Stingray Hydrofoil. Sounds like the 15 P is how I'll have to go being at minimum HP for that boat and keep the 17 P for spare. I run shallow alot in this Bay system and seem to nick the props often. Thanks in advance again!

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