Merc 115 4 stroke to 150 opti

[smoker62]

I am looking at the Manitou I posted in another thread. My buddy may buy my Southbay 522 but wants to repower to max 150. What kind of performance increase will he get ? I dont think the price difference would be worth it with 2 logs but I dont know. My current set up runs 25 consistently with 2 people. What would he gain with a 150 ?

[gramps]

Go on the web and type in, pontoon boat tests, and you will find a lot of testing for toons. You may get lucky and find your exact model.

[dockholiday]

Guess 32 to 35. Pretty sure my dealer said he got 35 with a boat same as mine but 2 log. The bentley is a pretty light boat though.
doc

[smoker62]

Guess 32 to 35. Pretty sure my dealer said he got 35 with a boat same as mine but 2 log. The bentley is a pretty light boat though.
doc

Doc, what do you see with your tri ?

[rbiederwolf]

Guess 32 to 35. Pretty sure my dealer said he got 35 with a boat same as mine but 2 log. The bentley is a pretty light boat though.
doc

I think this is about right. However this may be flawed logic, but here it goes.....

For reference. On my boat before upgrades - 2 log 115 Merc 4 stroke - best I could get was 24-25 mph. After adding center tune , and lifting strakes, I have gained about 6 mph 30-31.

Now I have been on my identical boat - tritoon strakes - with a 150 and it was right at 38 to 40 mph. If I back the improved performance that I got from the addition of the center toon and strakes, would put a two tube at 32 to 34 mph

Hows that for poor logic

[smoker62]

Guess 32 to 35. Pretty sure my dealer said he got 35 with a boat same as mine but 2 log. The bentley is a pretty light boat though.
doc

I think this is about right. However this may be flawed logic, but here it goes.....

For reference. On my boat before upgrades - 2 log 115 Merc 4 stroke - best I could get was 24-25 mph. After adding center tune , and lifting strakes, I have gained about 6 mph 30-31.

Now I have been on my identical boat - tritoon strakes - with a 150 and it was right at 38 to 40 mph. If I back the improved performance that I got from the addition of the center toon and strakes, would put a two tube at 32 to 34 mph

Hows that for poor logic

[smoker62]

Guess 32 to 35. Pretty sure my dealer said he got 35 with a boat same as mine but 2 log. The bentley is a pretty light boat though.
doc

I think this is about right. However this may be flawed logic, but here it goes.....

For reference. On my boat before upgrades - 2 log 115 Merc 4 stroke - best I could get was 24-25 mph. After adding center tune , and lifting strakes, I have gained about 6 mph 30-31.

Now I have been on my identical boat - tritoon strakes - with a 150 and it was right at 38 to 40 mph. If I back the improved performance that I got from the addition of the center toon and strakes, would put a two tube at 32 to 34 mph

Hows that for poor logic

Did you do the center log as a 3/4 or redo the whole transom for the true tri toon factory setup ? Where did you add the strakes and how the heck do you get them positioned optimally. I would imagine strake height and angle is a critical factor to get them to work as intended.

[dockholiday]

Guess 32 to 35. Pretty sure my dealer said he got 35 with a boat same as mine but 2 log. The bentley is a pretty light boat though.
doc

Doc, what do you see with your tri ?

40.........think the entire boat including motor is only 25 to 26 hundred lbs so it is light. the strakes get it out of the water pretty well.
doc

[rbiederwolf]

[

The dealer ordered the full tube with transom and lifting strakes fom the factory, and the dealer mounted it.

As for lifting strakes on the outer tubes, the manufacturer made them as well, shipped them to me, and I had those welded locally. We used the center tube as the template for location of the outer lifting strakes.

Since everything was made by the manufacturer, and dealer installed (at least the center tube) the factory rerated the boat identical to a factory tritoon Now I am rated for a 225hp

[rancherlee]

I'm willing to bet that he gains 3mph and 3gph more since its a normal 2 tuber. IMO anything over 90hp on an Un-straked 2 tube pontoon is waste of money. Seen many people jump from a 60hp to a 115hp and only gain 5-6mph, going from 21mph to 27mph. There are a FEW 150hp "standard two tube" pontoons running around Vermilion and I haven't seen one yet crack 30mph, and if I'm running a light load, can usually run right with them!

[Bamaman]

I agree that any twin toon w/115 hp or more should be straked and underskinned.
They effortlessly run a fast cruise with the nosecones out of the water, and strakes and underskin are very reasonably priced additions.

The 3rd toons are somewhat expensive, and they usually also require a $1K SeaStar hydraulic steering. They may handle better and carry heavy passenger loads, but they may actually cost you a couple of mph vs a straked twintoon.