Speed of 16' pontoon... slow??

[Jarvinen]

We just purchased a 2002 Crestliner 16' pontoon with a 2003 40hp Mercury Bigfoot motor. We're topping out at 9-10 mph with only two passengers. Isn't this a bit slow? We were expecting closer to 18-20mph.

Anybody with a similar pontoon/motor have comparisons?

 

[muskiemike12]

Re: Speed of 16' pontoon... slow??

What are your rpm's at WOT? What are you running for a prop? I don't think you will be able to hit 20mph with a 40hp, but you should be able to do 15mph.

 

[newbie4life]

Re: Speed of 16' pontoon... slow??

I have an old pontoon that we re-did last year. New floor, seating, top, and panels between the railings -- 16' floor, with a 40 hp yamaha. With 3 adults, and 2 kids, we can get it to around 14 mph, verified by gps. And that's with 3 - 12v batteries... 1 starter, and 2 for the trolling motor.

I struggled a little getting it to that point -- turns out I had to have the carburetors cleaned... twice. the first time, it was better... the second time it found some more junk. Could be a prop issue... but if the old owners didn't change the prop out, makes me think something else did change???

 

[WaterDR]

Re: Speed of 16' pontoon... slow??

I was getting 17 with a 23 ft Premier, 8.5 feet wide and seating for 16 with just me. BUT, that is according to the speedo and I never vrified with GPS. Had to be at least 15 though.

 

[figgyb]

Re: Speed of 16' pontoon... slow??

I have a 20' toon with a new 90hp evinrude. We get right at 21mph unloaded WOT. With 3 people + dive gear it will do 18mph. I generally run it at 3500rpm to save fuel and it does 12-14mph there.

It's my understanding from the local boat chatter that I should get another 2-3mph out of it by cleaning the toons (they feel like gravel ), and maybe another 1-2mph by underskinning as the 90hp is pretty heavy and brings down the back a good bit.

 

[mrbusdriver]

Re: Speed of 16' pontoon... slow??

I have a 18 ft. with a 40 hp Force and with 3 adults I get 17 on the gps.

 

[MH Hawker]

Re: Speed of 16' pontoon... slow??

I used to get 18 mph gps on a 20 foot and a 40 hp Nissan, and switched to 9.9 and am still getting 12. Both are 2 strokes.

So yes I would say you have a issue of some sort and the very first place I would look at is the prop. Find out what your WOT Rpms are if you don't have a built in tach you can pick up a hand held for around 20.00 at several places.

 

[WaterDR]

Re: Speed of 16' pontoon... slow??

Function of speed is the type of prop and the rate at which it rotates. A higher hp motor can turn a larger prop faster. As you add more weight (more load, heavier boat) the prop speed will slow. More hp can keep the rpms higher.

Here is a nasty thought, could your pontoons be water-logged? If so, they would have water in them and be very heavy.

 

[Jarvinen]

Re: Speed of 16' pontoon... slow??

Thanks for all of the responses. It sure sounds like we have some speed issues. We're having a mechanic take a look at it next week. We also have a "3 beep" warning alarm going off about every 5 minutes. Maybe that's associated with our lack of speed. I can't find anything in the manual about the warning though.

Pontoons full of water... didn't even think of that. How would you determine if there's water in the 'toons? It is very stern heavy but I thought that was just due to the large motor on a 16 footer. Maybe there is water in there.

 

[mrbusdriver]

Re: Speed of 16' pontoon... slow??

If the boat is on a trailer wiggle the boat side to side and listen for water sloshing around.

 

[5150abf]

Re: Speed of 16' pontoon... slow??

You don't have a speed issue you have an engine problem, anytime the the engine sounds a warning you need to have it looked and soon, the more you run the engine the more damage you can do to it, hence WARNING beep.

Google "mercury 3 beeps", it indicates low voltage, bad coolant sensor, idle air control or a fuel injector, the reason you are going slower is because the engine cut its power to limit damage.