Pontoon boat seems slower then it should be.

[donaldeclarkdec]

Hello, I have just purchased a 2005 24" Sweetwater Pontoon boat with a 115 Yamaha engine on it. The engine sounds good and runs good. This is the first boat I have owned/operated. I know pontoon boats are not usually speed demons by any means, but with just me an my dog on this thing it only goes aroud 17 MPH at full throttle. With me and 6 other people it still will go 15 MPH it doesn't make much sense to me. I'm not sure what pitch the prop is. I know it is a 3 blade and has a few small dings in it. I know this is probably slowing it down the original owner had the bottom half of the toons coated with some special paint (looks like rhino liner) I guess he would have it docked in fresh water bay and then cruise into salt water occasionally, thats why he had them coated he says. Any opinions or help with this would be greatly appreciated, Thank You.

 

[lncoop]

Re: Pontoon boat seems slower then it should be.

What are your RPMs at WOT? Is the bottom paint textured like Rhino? If so, that would slow you down without question. I would think you should expect around twice the speed you're currently getting out of her.

 

[FlyinGuy1017]

Re: Pontoon boat seems slower then it should be.

Start by checking your RPM's at WOT. Is the bottom paint actually textured? I've seen painted tunes, but never textured. Also, are you trimming properly? Could be a few things, but these guys will get you going in the right direction.

 

[H20Rat]

Re: Pontoon boat seems slower then it should be.

#1, as others have mentioned, check rpm.

Second thing is that your motor is probably way too low, especially if that is a 4 stroke. Pontoons in the last couple years have gotten good about putting a lot of setback on the motor, but... for whatever reason they aren't designed for the weight of a 4 stroke, plus people don't realize you do not NEED to hang the motor on the transom, it will mount perfectly if the top of the motor mount isn't hanging on the edge.

 

[donaldeclark]

Re: Pontoon boat seems slower then it should be.

yes the paint on the toons is slightly textured

 

[donaldeclark]

Re: Pontoon boat seems slower then it should be.

the prop is a 13 1/2"x15, and it runs 6,000 RPMS at WOT

 

[lncoop]

Re: Pontoon boat seems slower then it should be.

Not certain what your RPM range is, but 6k should be close to your max I would think, and definitely should get you more than 17 mph at WOT. Something else is wrong fo sho. Could be water in the toons, could be that coating, could be any number of things. Does the barge have a trailer?

 

[smokeonthewater]

Re: Pontoon boat seems slower then it should be.

I'm gonna say this is mainly a prop issue..... Spun hub maybe....

I doubt that the bottom paint is the culprit.... slick = slow

 

[2ndtry]

Re: Pontoon boat seems slower then it should be.

A Yamaha 115 (2.15 gear ratio) spinning a 15" prop at 6000 RPM and only getting 17 MPH has 57% prop slip. I would guess your tach or speedo is off, or you have a spun prop.

 

[V153]

Re: Pontoon boat seems slower then it should be.

or you have a spun prop

That's where I would start.

 

[donaldeclark]

Re: Pontoon boat seems slower then it should be.

Ok guys. Thank you for info. How can I tell if I have a spun prop.

 

[jmarty10]

Re: Pontoon boat seems slower then it should be.

Get a back up prop and put it on, go out and run the boat with it on. If performance is better than you know. You are going to need a backup prop anyways

 

[lncoop]

Re: Pontoon boat seems slower then it should be.

That's one way to do it. You could also draw a line all the way across with a sharpie, take her for a test run, then look for either the original line or newly broken up line segments. Then you'll know.

 

[donaldeclark]

Re: Pontoon boat seems slower then it should be.

Alright. I will get a new prop and try that. I guess I should have a back up anyway. What size and pitch should I get. Thanks guys.

 

[steelespike]

Re: Pontoon boat seems slower then it should be.

Try a 4 blade 14"

 

[lncoop]

Re: Pontoon boat seems slower then it should be.

Take a moment to run through this.
http://www.mercurymarine.com/propellers/prop-selector/#

 

[donaldeclark]

Re: Pontoon boat seems slower then it should be.

Thank you guys for the info. I appreciate it. I will keep you guys posted on how I make out.

 

[imported_John o]

Re: Pontoon boat seems slower then it should be.

If you have only 2 logs then you may be about right. Perhaps a couple MPH faster but not much. Remember that it is a displacement hull and it just won't fly.

If you have 3 logs then you should probably see about 25. (Even if you had lifting strakes etc a 115 is usually not enough motor to get full advantage of them)

As a point of reference I have a 175HP Yamaha on a 24' Manitou with performance logs (3), lifting strakes and underskinning. I get 38.8 MPH GPS top end.

Check over in the pontoon section of this board and also visit www.pontoonforums.com

 

[lncoop]

Re: Pontoon boat seems slower then it should be.

If you have only 2 logs then you may be about right. Perhaps a couple MPH faster but not much. Remember that it is a displacement hull and it just won't fly.

If you have 3 logs then you should probably see about 25. (Even if you had lifting strakes etc a 115 is usually not enough motor to get full advantage of them)

As a point of reference I have a 175HP Yamaha on a 24' Manitou with performance logs (3), lifting strakes and underskinning. I get 38.8 MPH GPS top end.

Check over in the pontoon section of this board and also visit www.pontoonforums.com

Don't think so. He should be getting a lot more than 17 mph.

 

[imported_John o]

Re: Pontoon boat seems slower then it should be.

Don't think so. He should be getting a lot more than 17 mph.

2 logs, 115HP, bigger boat. Maybe a few more (22MPH?) but not much more than that. He's got to push a lot of water out of the way to get moving. But then I'm not as familiar with 2 logs as I am with three. He'd need to check in over at pontoonforums.com and ask the pontoon experts there.