Trying to get more speed

[steelespike]

Looking at those pictures it appears the port side is deeper in the water.
​ May have water in the tube.

 

[edsjr01]

Big problem there is there isnt a drain, only access to the inside is on top of the toon......tried turning the boat upside down and shaking....didnt work so well

 

[steelespike]

You need to put it over your shoulder and whack it.
If its on a trailer you can syphon the water out.

 

[edsjr01]

Didn't try it over my shoulder....great tip!

I'm gonna run it tomorrow, will pull the plug out and have a look with a camera

 

[Jeep Man]

There are compartments inside the pontoon. Before you pull any plugs,remember they are there for a reason, primarily to let the pontoon adjust pressure in different temperatures, and are often hard to remove without destroying them. With the boat on the trailer, move it back and forth and have someone listen for water sloshing inside. Unless you have damage, a leaky pontoon on a 2011 Benny is unlikely.

 

[edsjr01]

It's a 2001

Update on speed.....I was wrong it's running 17 but the motor no doubt needs to come up. My goal is 23

 

[steelespike]

Calculator says a 9" prop turns about 5800 at 17 mph thats guessing 20% slip.
4 stroke big foot is 5500 - 6000.
If you try a 12" prop your rpm may be about 5200 probably too low.
An 11" may drop 400.At 5400 a 11" prop could make about 19 mph.
this all depends on your actual rpm and slip.

 

[HotTommy]

It's a 2001

Update on speed.....I was wrong it's running 17 but the motor no doubt needs to come up. My goal is 23

6 MPH doesn't sound like much. But that's a 35% increase in speed and not that easy to do unless something is dreadfully wrong with the current setup. Good luck.

 

[edsjr01]

I guess 23 is likely out of reach with this motor, this is a video of it running. I think it needs to be moved up a notch so at least the boat will respond to trimming. When I checked the speed yesterday attempting to trim it actually slowed the boat down.

Click on "Microsoft Services" for video

So I guess the new plan is to get the height right first then find out what the motor is actually turning and determine if I can change props.

I did speak to a dealer here saturday, they told me they put 11 pitch props on their 19 ft pontoons but not sure if that is with a bigfoot motor. As it turns out I do have a friend who might be interested in this motor, in which case I can maybe sell it to him and check into a 75hp Optimax

 

[Cat nip]

My 20 foot toon with a 89 60 hp evinrude goes 20 mph at 4300 rpm with a 15 pitch prop 21" logs. I am guessing I will lose some speed with the correct prop that hopefully shows up this week. My motor sits very high and vents some on very tight turns.

 

[steelespike]

Pontoons don't plane.My limited experience trim setting are more useful in controlling ventilation than hull attitude.My 18 footer.
If we assume your 60 is at an ideal setting 6 mph on a "planing" hull is unlikely. Even with a 75.On a 18' pontoon ; not going to happen.

 

[Silvertip]

I have an 18 foot with a 40HP Suzy four stroke and it runs 18 - 20. You were given correct info about tube length and diameter comparisons. Longer tubes provide more flotation for a given load than shorter ones. Your 60 HP engine is either tired or not running as well as you think it is. A 14 x 9 prop is also well in the ball park for a 40 - 60HP "Big Foot" engine but very wrong for a standard engine. The lower unit gear ratios are very different but that seems to be a non-issue since you are sure the engine is indeed a Big Foot. Also, tach settings on outboards do not correspond to the number of engine cylinders -- they correspond to the number of poles on the stator. A 12 pole stater on most outboards corresponds to 6 pulses on the tach sense line. Tachs may therefore be marked with the number of "poles" or the number of "pulses". Understand which one your tach is referencing. Pulses with always be 1/2 the number of poles. I can't see the tubes very clearly but the one I can see appears to have a fair bit of scale build up. That can cut speed dramatically.

 

[edsjr01]

I don't expect it to plane, I just want it to be right. Read my earlier post, i already agreed I'm not likely to get another 6 out of it with this setup. As for trimming out other boats and getting 6.......I've been in bass boats my whole life. Without a doubt there is at least a 5mph hour difference between trimming it out and not.

 

[edsjr01]

Motor isn't tired and has no issues running, starts right up and idles perfectly. I haven't changed the plugs in it this year, other than that it is fully up on its maintenance. Since this was my parents boat I also have full history on the motor, which was bought new in 2011. Mercury told me the tach needs to be set on 6P and I have verified that it is. I do think part of my problem is the boat was likely designed for a lighter 2 stroke motor and the motor weight of the 4 stroke is causing some of my problems......If I were to go to a 75hp Optimax the shaft will be 5" shorter, motor 50 lbs lighter and 15 more hp....that has to make a noticeable difference. Keep in mind switching motors isn't my plan unless I find I can do it cheap.

This week I'll likely move the motor up a notch, which if you see the video it needs to go up as the cavitation plate is below the water surface while under power.

That crap on those toons is going to be the death of me, I have tried a couple times to get it to come off and can't. That boat sat on a lake every summer in Wisconsin from 01 until 2010 when my mother bought it from a friend. I have a feeling whatever that is has something to do with that lake.

In the end, I really need to get the bow to come down......I think it sits way too low in the back.

 

[Silver Eagle]

We have a 2007 24 ft. StarCraft Pontoon Boat It has a 90 hp 2 stroke Mercury .We use it in the Chesapecke Bay mostly.. On an average cruise We travel around 16 mph. at 3500 rpm's But sometimes when I want to show off a little, I'll push it up to 22 mph at 5200 rpm's. I never red line it. This is with five adults. When I do this the bow really comes up out of the water .Makes people look.

 

[HotTommy]

I've run my 24' pontoon boat with three different engines. I never noticed the trim setting making any difference. .... And the trim setting that will most raise the rear of the boat and lower the front is .... no trim.

 

[Cat nip]

2 to 3 gallons of muratic acid should take that scale off in no time. The easiest way to bring the bow down is to remove weight from the rear and or add it to the front.

 

[edsjr01]

Pretty sure I tried muratic acid, didn't budge it

 

[Jeep Man]

Motor isn't tired and has no issues running, starts right up and idles perfectly. I haven't changed the plugs in it this year, other than that it is fully up on its maintenance. Since this was my parents boat I also have full history on the motor, which was bought new in 2011. Mercury told me the tach needs to be set on 6P and I have verified that it is. I do think part of my problem is the boat was likely designed for a lighter 2 stroke motor and the motor weight of the 4 stroke is causing some of my problems......If I were to go to a 75hp Optimax the shaft will be 5" shorter, motor 50 lbs lighter and 15 more hp....that has to make a noticeable difference. Keep in mind switching motors isn't my plan unless I find I can do it cheap.

This week I'll likely move the motor up a notch, which if you see the video it needs to go up as the cavitation plate is below the water surface while under power.

That crap on those toons is going to be the death of me, I have tried a couple times to get it to come off and can't. That boat sat on a lake every summer in Wisconsin from 01 until 2010 when my mother bought it from a friend. I have a feeling whatever that is has something to do with that lake.

In the end, I really need to get the bow to come down......I think it sits way too low in the back.

You ABSOLUTELY cannot use a short shaft motor on your pontoon boat. Should you want to try, be prepared for prop ventilation every time you go out. This is not a bass boat. Believe me I know. Been there, done that, as many others on this forum. The lighter weight and 2 stroke and more horses will help, likely 3 to 4 mph. To get the most out of your boat, go with the biggest 2 stroke it's rated for.and underskin it. Beyond that, you can put a contraption underneath for more lift and speed but at the expense of your wallet, smooth ride and control, or you can trade it in for a deck boat.

 

[edsjr01]

I didn't realize 5" would put that Optimax in the "short shaft" category, I guess I just thought the Bigfoot had an extra long one. Now for the kicker.....from what I have seen the 75 Optimax 2 stroke is actually heavier than the 60 Bigfoot. May still look into it, or just say screw it and get what I can out of this one then drink beer on it.

Looks like rain on and off all this week and its supposed to rain this weekend so it will likely be next week before I move the motor. Then take a good look at prop options once I can get an accurate rpm reading.

Underskinning is for sure an option, it boat has to be dragging it's arse a lot and I don't see how that wouldnt help. That contraption to go in between the toons looked like a great idea....then I saw the price, this project isnt worth 2k