Pontoon Speed Help

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Pontoon Speed Help

Here are some numbers to chew on regarding weight. I have an 18 foot Misty Harbor four-corner fish which is a very light boat as far as pontoons go. It is powered with a 40 HP Suzuki four stroke. The boat weighs 1100# empty. Add an engine (243#) and that makes 1343#. Add two batteries (one troller, one starting), the trolling motor, 18 gallons of fuel, all the fishing gear, and anchor and that adds another roughly 328# for a total of 1661. The trailer weighs 880# for a GVW of a little over 2541. Your boat is six feet longer, has a heavier furniture load and the trailer is longer as well so your rig will be pressing 3000# or possibly even more (larger fuel tank for example). My point is that the tires must be kept at maximum inflation pressure of 90 PSI to support that load. Yes -- you read that right -- 90 PSI (right on the sidewall of the tire). It is probably safe for your use but for high speed highway travel I would be a little nervous.
 

samo_ott

Vice Admiral
Joined
Jun 18, 2006
Messages
5,125
Re: Pontoon Speed Help

WOW finally found a forum on the subject I was interested in. I have a 16ft Playbouy with a 40 HP Force. I was able to hit 13.2 MPH...LOL from my GPS with the wind at my back.
I now amgetting under 10 MPH, I added some weight to the boat, by adding some wood under the seats to keep stuff off the wet carpet and a third 6 gallon gas tank.
So, anyone with at 16ft Playbouy and a force 40 HP tell me how fast it should really go?
No cavitation, but similiar to earlier post it seems like the last inch or so of throttle does nothing for the speed.
Does choppy water slow it down a lot?
Thanks, steve

I have a 16'er no name (8' wide) with an 1963 Viking 25hp and I get 15 mph (24 kmh) top speed on it.
 

JonathanEngr

Seaman
Joined
Jun 10, 2009
Messages
66
Re: Pontoon Speed Help

Yup--saw the 90 PSI last night when I went to check the tire pressure and my gauge (that goes to 50 psi) went off the charts.

At this point I have little choice but drive the boat back tot he lake (about a 30 min trip on rural roads). Once I drop the boat in the water I'll be able to get something done. Do they have trailer tires with higher ratings? Heck--is a single axle trailer stout enough to carry this boat??
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Pontoon Speed Help

You need to do a very careful summation of the various weights like I showed you, or have the rig weighed at a truck scale. Remember, published pontoon weight does not include and engine since the manufacturer has no idea what engine will ultimately be installed. I'm not aware of a higher load rating for that size tire. Again, for very infrequent use, the setup you have may be adequate. But if you are making longer range trips more frequently, you might consider converting the trailer to a tandem axle in which case you could use tires with a lower load rating (and less expensive) or you might just consider buying a new tandem trailer.
 

mayorjones

Petty Officer 2nd Class
Joined
May 24, 2009
Messages
110
Re: Pontoon Speed Help

What did you use to clean the tubes? They look awesome.
 

JonathanEngr

Seaman
Joined
Jun 10, 2009
Messages
66
Re: Pontoon Speed Help

Silvertip--I was thinking of calling the DMV today and see if someone could come by with a set of the portable scales to weigh my trailer while it's loaded. We've got quite a few logging trucks in the area, and I see DMV vehicles all of the time. Might be worth a shot? I did take it by a local tire store today (where I always buy my tires), and they confirmed basically what you said. However, they inspected the tires and the load, and felt that for the minimal traveling I do they didn't have any concerns. If I ever decide to travel much with this boat, I think it'd be worth the investment for a tandem. I've never owned a single axle trailer (nor one without brakes), and I'm not completely comfortable towing this thing.

Mayorjones--thanks so much for the compliment. As for what I did, it was surprisingly easy. I pressure washed all of the "gunk" off of the pontoons, which left me with the stained aluminum. I then used Sharkhide cleaner to remove the stains (amazing stuff!), then used the green 3M abrasive pads to rub out any vertical etching that had occurred over the years. Once that was done, I used a sponge mop with one of the pads underneath (the pads stay in pace via friction, and using a sponge mop helps distribute the pressure better than can be done by hand) and ran the pad from front to rear, rear to front time and again to smooth out any scratches. When all was said I done, I guess I had about 3 hours in it.

I can't take credit for any of it--pressure washing came from this forum, and the sharkhide cleaner and other steps came from the guys at sharkhide. It was perfect for me--easy and pretty darned hard to mess up!!! :)
 

mike243

Petty Officer 2nd Class
Joined
Apr 3, 2009
Messages
123
Re: Pontoon Speed Help

the easy way to ck the weight is go by a scrap yard,ask them to weigh it,pull up unhook & within a few minutes you will know what you need to know ;)
mike243
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Pontoon Speed Help

WOW finally found a forum on the subject I was interested in. I have a 16ft Playbouy with a 40 HP Force. I was able to hit 13.2 MPH...LOL from my GPS with the wind at my back.
I now amgetting under 10 MPH, I added some weight to the boat, by adding some wood under the seats to keep stuff off the wet carpet and a third 6 gallon gas tank.
So, anyone with at 16ft Playbouy and a force 40 HP tell me how fast it should really go?
No cavitation, but similiar to earlier post it seems like the last inch or so of throttle does nothing for the speed.
Does choppy water slow it down a lot?
Thanks, steve

Glad to have you aboard; but you need to do your own thread it gets very confusing for all aboard as Qs and As accumulate.
 

JonathanEngr

Seaman
Joined
Jun 10, 2009
Messages
66
Re: Pontoon Speed Help

SUCCESS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Boy--what a weekend! We headed up this past Friday to the lake--me in the lead to get things ready and the rest of the crew due about an hour later. My goal was to get things prepared quickly and get the boat on the water to test the hydrofoil and clean 'toons, and then add the prop for further tests. Well, that didn't happen. I got the place, and before I even got the boat in the water the first crew arrived. I decided to go ahead and put the prop on while waiting for the rest of the company to arrive, and boy--that went over like a bag of bricks with my wife. "You're wasting time!", and "What if you do something wrong/break something and all of these people arrive with no boat to ride??" and so-on. Tsk, tsk, tsk. But I was undaunted! With the help of my brother-in-law, we changed out the prop (first for both of us) in about 5 mins. I was actually worreid that we'd done something wrong because it was so easy. Anyway, it worked flawlessly.

So, here was the load on Friday: Me (about 205 pounds), my brother-in-law (an easy 230), my wife (skipping this one just in case...LOL!), her sister (maybe 140), her two daughters (say 90 pounds each--they're 10 and 12), my two kids (45 and 55), my wife's friend and her daughter (another 140 and maybe 60). We also brought two towables, two large coolers filled to the brim with drinks and ice, another one with food, and a few misc items--say another 100 pounds. So--that's 1255 pounds. Let's just say, for argument's sake, that my wife adds another 100, bringing the total to 1355 pounds. We hit the water, and boy--it was a veeery turbulent day. In case anyone on here was on Lake James (Marion, NC) that day, I'm sure they'll attest to it. Despite this fact, the trusty old GPS shocked me when we hit the open water and I went WOT (now at 5100-5200 RPM)--16 MPH!!!! A solid 16. It hit 16 and stayed there until I throttled down. We went to a cove, swam a bit and dropped in one of the towables. We tossed my daughter and one of the bigger kids on it, and I went WOT again. It solidly hit 15, and even jumped to 16 mph here-and-there, but would drop down to 12 mph in a hard turn.

Now--16 mph certainly isn't going to fill your teeth with bugs, but think about this (it's what was going through my mind until today!)... my previous top speed (GPS, of course) was 16-17 mph unloaded. If this thing was hitting 16 with an extra 1200 pounds, what would it do with just me? Better yet, I don't know if it's the result of the prop for the hydrofoil (my guess is the latter since it come out way over the prop thus keeps more water above the propeller where the exhaust exits), this thing is much, much quieter at WOT. Before, once I went past 4100-4200 RPM, it went from a deep, throaty sound to a weed-eater whining sound. If this had been the only improvement, I'd have been happy. Also, the same thing occurs in tight turns. The exhaust sounds deep, muffled and throaty, whereas before it really went to a screeching high-pitched sound--even at 2500-3000 rpms.

I don't even want to talk about Saturday and Sunday. I came down with a stomach bug and was completely beached. Ugh.

So--today popped up, and although I was feeling a bit under the weather, I just had to hit the lake. I went out on the water about 11:00, trying to beat a storm that seemed to be approaching. The waters were pretty calm as was the wind, with maybe 6-inch ripples all over the surface. I loaded up my son (4 years old) and me, and puttered out to an open waterway about a mile long. After telling him to sit down, I laid down on the throttle. It hit 16 mph by the time I was near 4000 rpm, and I just knew I had to hit 20. A few seconds later "20" popped up on the GPS, and a second or two after that, ****21****!!!!! I kept the throttle wide open, and it sat on 21 the whole time. Nearing the end of my run, I throttled down, made a hard left, waited for a jet ski to zoom by, and hit it again. I wanted to make sure it wasn't "wind assisted" (I really couldn't tell which direction the wind was coming, although it was a steady breeze). Once again, it jumped right up to 21 and stayed pegged there until I cut back on the throttle. I was ecstatic. I was grinning and slinging "Oh yeahs!" so fervently that my son joined in. After getting back, I informed my wife of my success, undoubtedly akin to breaking a land speed record, but she just didn't seem to understand. I did get an eye roll--at least that's something!

I had promised pics of my GPS, and I'll try to get some on Wednesday when we head back to the lake. Until then, I'll be grinning like a little kid!
 

JonathanEngr

Seaman
Joined
Jun 10, 2009
Messages
66
Re: Pontoon Speed Help

Mike--

Great idea! I'm not sure if we have any scrapyards nearby, but we *do* have a landfill. How accurate would the scales be? I was driving loads across it weekend after weekend when we remodeled out first home. I can just drive across with trailer in tow, get weighed, drive off and unhook the trailer and then get weighed again. I'll look into it.
 

Nogotboat

Recruit
Joined
Sep 21, 2008
Messages
5
Re: Pontoon Speed Help

Hi, thanks Admirl, not sure how to start a thread. Anyway my Force 40 died, got a new Merc 4 stroke 40 HP EFI. Went from 13.8 MPH to 19.2 MPH on my 16ft playbouy. Holds spped much better now in rough water and more weight on boat. Very quiet, can now hear my stereo even at WOT.
 

mayorjones

Petty Officer 2nd Class
Joined
May 24, 2009
Messages
110
Re: Pontoon Speed Help

After all that, I'm not real sure what the hell actually happened with this deal but it was sure entertaining reading!

So the prop you went with is a 12 pitch? I have a 21' pontoon with a 50 hp Mercury and have a 9 pitch, but my RPM's run in the mid 5k's...

Glad things turned out so well for you. Gives the rest of us hope :)
 

pontoonokie

Seaman Apprentice
Joined
Apr 8, 2009
Messages
41
Re: Pontoon Speed Help

great news .. gives me hope.. how about a pic of the motor in is current setup on the boat... also what kind of hydrofoil did you go with
thanks
curtis
 

mayorjones

Petty Officer 2nd Class
Joined
May 24, 2009
Messages
110
Re: Pontoon Speed Help

Yes, I would be interested in more info on the hydrofoil as well. Much of what I've read on the Internet speaks poorly of them when talking about pontoons. It would be interesting to know if this success story was more so due to the prop or the hydrofoil...
 

DMAN1968

Seaman
Joined
Apr 18, 2004
Messages
54
Re: Pontoon Speed Help

When I had the 50 hp Johnson on the back of 24 foot Lowe it would ventilate badly when I took the hydrofoil off. It was set at the lowest setting with the correct prop but just wouldn't go without the hydrofoil. When I changed over to the 115 hp I tried the hydrofoil on it but it seemed to push the bow down too much so I removed it from that setup. It may be that engine size plays a big part as to if the hydrofoil works or not. I had to have it on the lower horsepower engine.
 

mayorjones

Petty Officer 2nd Class
Joined
May 24, 2009
Messages
110
Re: Pontoon Speed Help

Which is why I'm asking - I have a 50 hp on a 21' and deal with ventilation. Wondering if someone could give me a suggestion on a hyrdrofoil, or are they all pretty much the same?
 

DMAN1968

Seaman
Joined
Apr 18, 2004
Messages
54
Re: Pontoon Speed Help

Sorry about that. My toon came with the 2 piece fins that fit on either side of the foot...not sure of the namebrand...maybe Doelfin. I would think that the one piece design that fits all the way around the foot would help to hold water at the prop better (just my opinion though). Since you are not looking for the same performance gains as a regular planing boat, but just hoping to reduce ventilation, I wouldn't shoot for the most expensive. I don't think it's going to matter a whole lot as to the design for ventilation issues.

Hope this helps.
 

mayorjones

Petty Officer 2nd Class
Joined
May 24, 2009
Messages
110
Re: Pontoon Speed Help

I've been reading up on them and am really unsure if it will help or not... From what I've read, it seems they are designed to keep the nose of the boat down, while I'm thinking I might want to keep the nose of my boat up more to keep the prop in the water, but there I go thinking again ;) ...
 

SeanT

Senior Chief Petty Officer
Joined
Jul 8, 2009
Messages
661
Re: Pontoon Speed Help

Great thread - I don't have a pontoon boat myself, but my dad does. It's a 24' (I think) Princecraft with a 60hp Merc (I think). Not long after we got it, he dragged me around on a kneeboard a few times, just to see if we could. I don't know for sure what his top end is, but I think he was struggling to maintain 18MPH when he was dragging me - there was noone else on the boat and it was hard work for me!

Anyway, glad to hear about the success - and I just needed to add a WOW about the pontoons - I don't think I've seen pontoons sitting in the showroom that look that good....
 
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