Porpoising Issue
 

I have a 2015 Mako 18LTS with a 115 Optimax. I'm not able to trim up much without popoising. Jackplate is down and I've moved all the weight I can to the front. I've been thinking about adding a permatrim.

Anyone have any experience with permatrim hydrofoils?

Try a prop with less bow lift/less rake. I have a low rake prop on the way to my house this week to try to lower my bow and let me trim more neutral and not stay tucked under.

Jack plate may be to low. I found on my boat 1/2" to low cause bad porpoising.

The boat has a type of tunnel hull, vented tunnel I think it’s called. With the jackplate all the way down the motors cavitation plate is level with the top of the tunnel. I’ll take it out this weekend and try different levels with the jackplate.

A hydrofoil is just a bandaid. What motor are you running and what's your rpm and speed at wot?

I'm running a 115 Optimax ProXS. WOT is a little over 5,000 rpm. I'm not able to get it higher due to the porpoising. The max I have gotten it was 5,200.

I see on the Mako website that if you get the 115 the boat is required to have trim tabs. It was an option when I got mine. An option I didn't get of course.

Trim tabs are a little pricey but will save your back and of coarse stop the bounce!

Attachment 115542

This is a pic of the factory tabs.
Below are pics of my transom.

Attachment 115543
Attachment 115544

I don't know about mounting the tabs to the bottom.


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Could be a prop problem or a motor height problem. Sounds like you may be running with your motor a little too low

I have manual jack plate and when I started playing with it, 1/2" low it'll bounce with no trim, now I can trim up until it blows out no chance of porpoise. trial and error!

I need to spend some time behind the wheel. It's a shame I've had the boat going on 2 years and only have 26 hours on it.

I went to Toledo Saturday but it was to cold to play much. This coming weekend looks better.

I have a Blue Wave and it runs smooth with no bounce with the Jack Plate in any position. There's a good prop shop in Bridge City(Coastal Prop Shop) that knows a bunch about boats and usually has good suggestions. Also, I replaced my stock prop with a PowerTech prop and those guys were extremely helpful in finding the right prop for my boat. Between the two they may be able to help if it is a prop issue.

Thank ya'll for the help and input.