looking for some input from the Gurus.

[docster]

Decided to get a pontoon for the wife and her friends as a party barg, and keeping the procraft since its in such good shape it would have cost us 25-30k to replace with something as nice as it (we are original owners and its meticulous).

The Boat: 1993 Procraft V-180c (fish ski) with 1991 Mariner 115 4 cyl outboard (2 stroke) with 19 inch 3 blade al quicksilver prop.
Primary uses: cruising lakes/rivers, pulling tubers, wakeboarders, occasional skier.
Problems with the boat: Porposing, high planing speed (22-25mph)
What i Want out of it: More low end pull for getting skiers up, and tugging tubes around, lower planing speeds to save gas (16-20 mph), no more porposing.

So right now the anti-cavitation plate sits perfectly level with the pad. If I trim up at all over 25 mph, its starts porposing, worse the faster i go. right now, when wakeboarding, its really hard as a driver to keep the speed steady, at 18mph, not on plane yet, so its either starts planing out and picking up speed, or it starts slowing down from drag. The little 115 really does a great job getting up on plane, but a little more low end would be nice to save me some fuel.

I was thinking about trying a hydrofoil, but I dont think thats what I need. Would Nauticus SX tabs be a good choice? Dont wnat to drill holes in the boat, but if it will make a BIG difference, then so be it. Might reprop it if i can find a good cheap used 4 blade or high five. Not going to repower the boat, its not worth it to me (the boat is 20 years old, and the mariner runs flawlessly). What is best option to keep the planing speed lower, and help improve fuel economy a little bit. Thanks for your help in advance.

will trim tabs even fit on the boat?

 

[Jlawsen]

Re: looking for some input from the Gurus.

The 115 is a two stroke 2+2. It runs on cylinders 1&2 up to about 1700 rpms and then wham, 3&4 kick in. If you keep that motor the best thing you can do is move it back at least 5" with a Jack Plate. Hydraulic would is always the nicest way to go but manual can be setup just as well. Once you get the motor back into cleaner water and get the height exactly right the problems should go away. CMC makes a nice plate and so does Bob's Machine. I'm not a fan of the Panthers but a lot of people seem to like them.

You're problem won't likely be cured with a hydrofoil or smart tabs. I think you need to get the engine back into less turbulent water.

 

[docster]

Re: looking for some input from the Gurus.

correct, it has the 2+2, however, when the throttle is all the way open, it fires up all 4 cylinders no matter the RPM. Jack plate sounds nice, but sounds like a ton of work.

 

[roscoe]

Re: looking for some input from the Gurus.

Jack plate isn't that much work, but may involve a lot of tinkering to get it right.
May need new steering cable to reach the new motor location.
Probably need a new prop as well.

Tabs may help a little, but getting up on plane kind of defeats the purpose for wake boarding, doesn't it?

I think you should post this in the "prop" forum, and see if any of those gurus can give you some specific suggestions.

They may also want to know the wot rpm with the current prop.

 

[26aftcab454]

Re: looking for some input from the Gurus.

I would think a smaller pitch 17" prop and keep the trim lower . also a tail heavy boat may porpise at speed. Jack plates and transom bracketts are great but $$$.