Engine swap on pontoon

[Tim63]

I've only had a couple of posts, so I'm still newbie. Around April we purchased a 22' Harris Flote Bote pontoon. It has an aluminum deck and is powered by 3.0L Mercruiser I/O. I would like more power. Is the 4cyl to V8 swap really that difficult? I have done numerous s-10 V8 swaps so I'm not new to making a few things if need be, ie mounts. The pontoons that were built with v8's are still more money than I want to spend unless necessary.

 

[crb478]

Re: Engine swap on pontoon

If you can fabricate everything it is doable, but I don't think it will be easy. You will need the new motor and outdrive, and they will need to be set up at the right heigth, so if yo have access to a factory set up that would be helpful. The V8 weighs more and the out drive needs to be set at the proper height in the water. Its hard to set it up based on how far you think the back well sink into the water

 

[Tim63]

Re: Engine swap on pontoon

Wouldn't the out drive be the same as the alpha 1 that is in it now, but geared differently? Mounts should be only problem. I was thinking of a waterglide possibly to offset the weight. They advertise 800# more flotation. I have complete mercruiser 5.0/w out drive.

 

[crb478]

Re: Engine swap on pontoon

It uses a different gear ratio, but if you have the complete drive train why not try it? See if you can incorporate the motor mounts to have some vertical movement in case you need to raise it an inch or so, and then set everything up at the current outdrive heigth. It may work fine, if not try adding some weight to the front of the boat temporarly. This will raise the outdrive and give you an idea of where it will run best. It will take some testing to dial it in, but I see no reason it should not ultimately work

 

[Bamaman1]

Re: Engine swap on pontoon

FYI: High performance major brand tritoons with large V-8's are about $75K, and they're built heavy and stressed to handle the punishment those engines will produce.

If you're wanting more performance, sell your boat now, and be prepared to step up to a tritoon and a big outboard.

 

[Tim63]

Re: Engine swap on pontoon

I was thinking 200-230hp not the higher hp V8. The 4.3 V6 might be enough. If I bought new Mercruiser engine and drive, I would still only be at 13-14K in an all aluminum, I/O 200hp pontoon with new power. I may be crazy for considering this swap. If I have to buy another boat, I will.