Help setting my tritoon up with my new yamaha 150

[horizonlawn]

I've got a 02 landau elite 22.5 ft tritoon, came with a 90 hp merc 4 stroke, went pretty well with the 90, could do about 28 mph empty, but loaded it would fall on its face pretty bad. so i spent the summer looking for a 150, and finally found one. its a yamaha 150 fourstroke, got the motor on the boat and ran it with a 14 x 19 prop, a little big but it came with the motor so i figured i would try it to get an idea of where i needed to be. so i ended up trying a 15 x 15 solas aluminum prop which seems to be close, its running at 5400 rpm and 37 mph. which isn't to bad, but it seems like i should be into the 40's with this motor. the thing that i'm now concerned about is the extra weight in the back of the boat, a little over 100 lbs seems to really squat the back of the boat in the water, and even when i'm wide open the but still doesn't seem to come up and out like it should. this was one of the early tritoons where they weren't extending the center tube past the back of the boat, its mounted like any standard pontoon would be. does anyone have any experience doing the extension of the transom, would the extra flotation in the back help me, or is it more work than its worth. the boat goes good, but if i can get a little more out of it its worth the effort, also it seems like i should be able to pull a 14x 17 prop with that motor, but based on my rpm with the 15" i dont think i could, which suprises me because i had a 14 x 13 on my 90 hp. any help would be great thanks

 

[5150abf]

Re: Help setting my tritoon up with my new yamaha 150

A 9 mph jump is pretty good and I really don't think you will get more than that, speed on water, especially with a toon, is hard to come by.

I make extended transoms all day long, on new tubes, that isn't something you can add to a tube at least for anything you are likely to pay.

I don't really pay alot of attention to what other companies are doing but I am pretty sure all the center tubes out there are one peice and not added to the tube, it just isn't something you can do and as a welder with 25 years and 100,000 boats under my belt I would really reccomend you don't do it.

Even with all my equipment and experience I really don't see how you would do it othe than buying a new center tube.

 

[The Rooster]

Re: Help setting my tritoon up with my new yamaha 150

+1 ^^^. Do your tubes have the lifting strakes? They make a difference.

 

[campyman]

Re: Help setting my tritoon up with my new yamaha 150

5150 why cant he remove center tube and put a new longer one with lifting strakes and better floatation it seems to me his problem is "furrowing" instead of floating.. Roster how fast is your 250 optimax toon?

 

[horizonlawn]

Re: Help setting my tritoon up with my new yamaha 150

I will have to post some pictures of how my center tube is made, its two pieces, the front 2/3 is like the other 2 tubes, but the last 1/3 is a little shorter depth wise and is a separate piece, it is an actual pontoon, not a motor pod, but is only 6 ft long, do lifting strakes make a big difference, that was another option I wanted to look into, I'm fully capable of building a new extension transom tube, but its a lot of work and I don't want to go through the trouble if its not worth it. Also what should I expect to see for speed with this set up, the bot dry only weighs 1800 lbs ?

 

[campyman]

Re: Help setting my tritoon up with my new yamaha 150

Hey check out thread about transom towing, a reply from Motons in Motion inc says the do custom work on a regular basis

 

[Rancherlee]

Re: Help setting my tritoon up with my new yamaha 150

your current setup matches the math almost perfectly. In theory, when doubling the HP you gain half the speed. 90 to a 150 is a 67% jump in HP. Half the difference is 33% gain in speed, which in your case is 37.3mph Dang near right on the nose of what you DID get. Since you seemed to loose a lot of speed with only a small load added before that tells me you well getting up on top the water with the 90hp so the number would be comparable. There are all kinds of tricks for get more speed, UNDERSKINNING #1! , jack plate to move the motor back and up a bit, rerouting cables to reduce drag. I think 40mph MIGHT be possible if everything is tweeked. Moving the motor back helps handling buy lifting the nose more which means it pushing down harder on the back, think Giant lever. Its usually worth the trade off. If you REALLY want to see an UNLEVEL pontoon search for the one with triple 300's on the back on youtube.

 

[5150abf]

Re: Help setting my tritoon up with my new yamaha 150

Like I said, I don't pay alot of attention to what other comanies are doing and I have certainly never heard of anything like that so get some pics up, I am really curious, sounds like an odd set up.

I wasn't doubting your abilities, it is just alot of work for somehting that may or may not work, hydrodynamics are really funny and even the R&D guys at work miss alot, seems like something will work really well and then it does the exact opposite of what they want.

Unfortunately the only way to tell is to build it and see what it does.

Campy, he can do that but it is going to cost @ 2K for a new center tube, probably no the kind of money you want to drop on a 10 year old pontoon.

 

[Bamaman1]

Re: Help setting my tritoon up with my new yamaha 150

Tritoons with 150 hp Yamahas and lifting strakes usually see between 37 and 40 mph. You're not far off your max speed. Over 115 hp usually see SeaStar steering and stainless steel propellers.

I would suggest changing to a Yamaha Reliance 15 pitch stainless prop and you should be looking for 6000 rpm's. Some dealers are better than others when it comes to props. Some major markets have propeller shops, and their expertise is free if you buy a prop from them. I've seen the Reliance props @ $453 online.

 

[Rancherlee]

Re: Help setting my tritoon up with my new yamaha 150

As far as reliance props go, check out Turbo or Stellito props for a match. Yamaha bought them out a few years back and most of the Yamaha props are just relabeled Stellito/Turbo props.

 

[craigmack]

Re: Help setting my tritoon up with my new yamaha 150

horizonlawn, is that speed via speedo or GPS? Granted my setup is different but I also have a 150 with roughly the same size prop and our numbers are about the same. I haven't used GPS with the prop I'm currently using but the speedo reads 40 MPH @ 5500 RPM. I'm thinking mine will GPS at 37/38 MPH with two adults and 30 gal of gas.

 

[horizonlawn]

Re: Help setting my tritoon up with my new yamaha 150

my speed was gps, i guess the speed isn't the only thing i'm trying to change, the back of my boat is sitting pretty low, and wide open i can't seem to get enough of the boat out of the water unless i trim it up to high, no really solving my problem. also shouldn't my boat bank in the turns, it just stays flat, and makes it hard to steer. i don't have hydraulic steering yet, but its next on my list. I think my next step/project is going to be a different trim tab setup. we'll see how it goes. also i do not have lifting strakes which would probobly help, but it seems like it would be a ton of work, and i have foam filled u-toons

 

[craigmack]

Re: Help setting my tritoon up with my new yamaha 150

Lifting strakes would help with riding higher at faster speeds but to lean I think you need the center toon to be either lower or larger than the outside ones.

 

[The Rooster]

Re: Help setting my tritoon up with my new yamaha 150

Lifting strakes would help with riding higher at faster speeds but to lean I think you need the center toon to be either lower or larger than the outside ones.

+1 ^^^ or sometimes they remove the outer lifting strakes and keep the inner ones which allow for some banking through turns.