All propped out

[Catfish73]

I have an Alweld 18’x89” cc boat. Hull weight is 1040 #. Figuring battle weight at 2200#. 2017 mercury 115 4 stroke with a 2.01-1 gearbox and WOT rpm of 5-6k. I’m trying to find a good prop for this boat, so far I’ve tried :
13.5 x 24–Will run on plane but only 4500 RPM
13.5 x21–Blows out
13x19 —Blows out
I’m looking for some info if anyone has a comparable set up.

I am running a Bobs hydraulic Jack plate

 

[airshot]

Lower your engine...height will change with each different prop.

 

[Catfish73]

With the hydraulic Jack plate I can put the engine near under water. I’m pushing a lot of weight without proper diameter, pitch. I’m looking for someone who’s running same ( or near) setup. Thanks for the input.

 

[GYPSY400]

What do you mean " blows out"
Like cavitation?

 

[Zum]

Shouldnt " blow out", like you say by dropping a few pitch. Sounds like maybe your prop isnt in the water far enough or the hull is disturbing the flow yo the prop?
Not sure, maybe a prop with some cupping or a compression plate to get water around your prop.

 

[Catfish73]

What do you mean " blows out"
Like cavitation?

Yes, it cavitates horribly.

 

[Catfish73]

Shouldnt " blow out", like you say by dropping a few pitch. Sounds like maybe your prop isnt in the water far enough or the hull is disturbing the flow yo the prop?
Not sure, maybe a prop with some cupping or a compression plate to get water around your prop.

 

[Catfish73]

Hopefully got it figured out, I’ve never had a big heavy sled of a boat like this one.The pods I welded onto the back are creating a hole in the water at the transom so I put on a cavitation plate. Hopefully will help. I appreciate your thoughts.

 

[Zum]

I dont have pods but read a bit, most people say there not really in the water much when on plane....angled up from the stern
Google compression plates, alittle different then a cav. plate....same thing with them mostly out the water when on plane.