Prop/hub spinning?

[MonteSS]

Buddy has a 95 Procraft V170b with a 95 Merc 115 4cyl 2stroke. Runs good but out of the hole seems to slip. Motor revs high and boat is slow to get on plane trimmed down. Sounds like cavitation possibly? It does have a small plastic hydrofoil thingy on it. Prop is stainless Quick Silver 13.5 x 22 and externally in good shape. No jack plate.

Can the hub sin in the prop?
What would you look at first in our situation?
Thanks!

[21XDC]

Over venting, Motor too high, Bad prop repair, worn out cup, etc. Close some PVS holes if possible. Maybe try a trophy plus 21P

[MonteSS]

Ty 21XDC.

Friend is not looking for top end performance and just wants a "normal" launch. My 75hp 1995 Merc (stock Merc Black Max) does not seem to have and vent holes like you mentioned.

Saw his boat yesterday and took the small hydrofoil of to start.
His Stainless Quicksilver prop has three square/rectangle holes at the front between the blades. Should I put tape over then as a test?
Here are some picks. Ty

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[21XDC]

Only if the rpms are over 3800 on holeshot. Tape wont stay on for a single holeshot. I've tried aluminum tape too...

[lpugh]

^^^^^ plus 1
pig putty epoxy will work for a while for testing, plug one hole at a time to test, don't think it will get on the pad when you reduce the slip
what is the rpm at WOT trimmed up, I think you will need about a 19P prop for that boat

[21XDC]

Try a 17-19P Trophy plus if you can.

[lpugh]

^^^^^^plus 1

[MonteSS]

I found a Trophy Plus 17 like new on Ebay for $350. He went with that and a new hub kit and all seems good now. Local lake has speed limit so he will have to try another to get WOT RPM's. Ty all.

[PatriotAW4]

That prop is fine, he needs some vent hole plugs. Plug 2 holes and it should do much better.
https://partsvu.com/products/mercury...4aAvpeEALw_wcB

[Rich1]

I would get that prop fixed before I tried anything. back edge isnt round and the leading edges of the blades are beat up pretty good. Leading edges like that can cause a lot of cavitation due to them generating air bubbles.