Prop selection

[JasonD]

Just put a Jackplate on my boat and can't get on plane as it sits now. The water comes to just under the cav plate when planing so I'm not convinced it needs to be lowered yet. I was also told my aluminum prop had too much flex to run on top like this, that true? Trying to get this setup for a hunting load running rivers so speed isn't much of a concern as pushing the load. Should I lower pitch for the load and add heavy cup?

Hull: 14x32 light riveted
Motor: '77 15 Johnson
Prop: solas 11 pitch, no cup added yet until I decide on buying a stainless
Cav plate is aftermarket
RPM's unknown but was running 24 with just me on 11 pitch before raising motor.
Have had tank and battery sitting in the middle of the boat to help planing

 

[RustyGoat]

from the research I've done trying to decide on a prop for my boat the difference between aluminum and stainless props on small hp motors isn't noticeable and not worth the extra money. A 15 hp motor isn't going to have even remotely enough power to make an aluminum prop flex.

 

[stevesecotec02]

Your 15hp should easily plane out a 1432 jon. I had an 8hp on a 1432 and it would plane with 2 people. Are you running with the motor tilted all the way down? You need to experiment with the trim by trying diffrent mounting holes. An aluminum prop is fine and you mentioned running rivers if the water is shallow in spots do not put a stainless prop on there. Aluminum props can save your lower unit if you hit a rock as the prop will give first and that may not happen with a stainless prop. I have run solas amita props for years and never had a problem out of one. Take some pics of your setup and maybe we can spot a problem but. How well is your motor running I just cant see a 15hp having any problems planing a 1432 riveted jon. Your boat probaly weighs under 200lbs bare hull add in two guys gear and a battery and you should still see close to 20mph.

 

[JasonD]

Ran fine with the motor clamped directly to the transom but with the jackplate raising it things change. Was seeing 24 easy on solo runs before the change

 

[stevesecotec02]

If it ran good before jack plate raised the motor than you need to lower the motor. Some setups run better with cav plate 2 inches above bottom of hull others 2 inches below. Its all trial and error untill you find that sweet spot. The prop shouldnt need changed just because you added a jack plate. I see you said you have an aftermarket cav plate? Are you talking about a whale tail/ hydrofoil? If so if its not set at right height it wont allow you to get any bow lift at all and you would be plowing water the whole way.

 

[whitetailhntr]

What constitutes being on "plane"?