Engine height on transom

[ianstanley]

Hi
Just bought a Bennington 2075 2007 model and about to fit a new Honda 50hp 4 stroke. Although been power and sail boating for 30 years this is my first pontoon boat (not many in the UK) so I need some advice on what height to set the engine/cavitation plate re the pontoon bottom and also what pitch propellor is recomended.
Also any recommended antifouling as this will sit in marine (salt water) most of the year, a bit nuts, I boat in winter as well!
any help appreciated, thanks Ian in Poole, Dorset, South of England UK

 

[Jeep Man]

Re: Engine height on transom

First off, the engine has to be a "long shaft" version. The anti-cavitation plate should be just below the bottom of the transom. Can't give you much help on coatings for the pontoons, but I'm sure some of our coastal friends will chime in. The engine should be a salt water version as well, be tilted up when not in use, and flushed after use.

 

[Silvertip]

Re: Engine height on transom

Mercury makes two types of lower units for their 40/50/60 HP outboards. One of them is called a Big Foot which has different gearing than the standard lower unit which typically has a 1.81:1 ratio. Big Foot motors have 2.33:1 or 2.0:1. Big Foot motors are the preferred engine for pontoon service as they can swing much larger propellers (14 inch vs 10-1/2). Mercury also makes an excellent pontoon prop that has very large blade area, roundish shaped blades and due to the design offers much better thrust both forward and in reverse. Standard Merc lower units have been used successfully but there is a much greater chance of prop ventilation. That depends entirely on the design of the engine pan, load, water conditons, load distribution etc. On a pontoon you generally want the engine installed as low as possible to avoid ventilation. As for props, if you have a Big Foot motor, a 14 x 11P is the prop you need. If you have a standard lower unit it is strictly trial and error but I would tend to suggest a four blade with lots of cupping.

 

[ianstanley]

Re: Engine height on transom

First off, the engine has to be a "long shaft" version. The anti-cavitation plate should be just below the bottom of the transom. Can't give you much help on coatings for the pontoons, but I'm sure some of our coastal friends will chime in. The engine should be a salt water version as well, be tilted up when not in use, and flushed after use.

thankyou for that
Ian

 

[mayorjones]

Re: Engine height on transom

With that said, is there anybody out there using the Bigfoot and, if so, where to you have it mounted? I recently switch to the Bigfoot model and have it mounted in the middle hole, but am wondering where anybody else has found successful mounting?

 

[Jeep Man]

Re: Engine height on transom

With that said, is there anybody out there using the Bigfoot and, if so, where to you have it mounted? I recently switch to the Bigfoot model and have it mounted in the middle hole, but am wondering where anybody else has found successful mounting?

How's the new motor working out. I hope it's an improvement over it's predecessor. I'm running the same motor as you on a 20' Sun Tracker with 26in. toons. My setup is one down from the top. With it ALL the way down, the steering linkage was rubbing on the carpet. How's yours in the middle hole, any ventilation?

 

[boatmor]

Re: Engine height on transom

It is my understanding from talking to dealer that for a pleasure pontoon that they should be mounted as low as possible since the biggest problem with pontoons is keeping the prop in the water. A high powered performance toon should have the engines mounted higher since for one thing those engines are HEAVEY. just take a look at these http://picasaweb.google.com/shootmor/HotAndColdToons#

You should use a prop made especially for pontoons.

 

[mayorjones]

Re: Engine height on transom

How's the new motor working out. I hope it's an improvement over it's predecessor. I'm running the same motor as you on a 20' Sun Tracker with 26in. toons. My setup is one down from the top. With it ALL the way down, the steering linkage was rubbing on the carpet. How's yours in the middle hole, any ventilation?

The new motor works great. I haven't had it loaded with people - it works well (so far) mounted in the middle, but I'm thinking I might have it dropped one hole just to be safe. Beyond that, I've been very happy with the motor.

Thanks for checking Jeep.

DJ

 

[chiculyup]

Re: Engine height on transom

Life is too short to be serious, laugh it up.

 

[southernboater]

Re: Engine height on transom

I have also recently purchased my first pontoon and intend on using it in salt water. In addition to painting the toons, Manitou recommends anodes on each of the toons.