Whaler Central - Boston Whaler Boat Information and Photos

Posted by Dsmith181 on 01/13/24 - 11:40 AM

Hi, I was looking to repower my 1978 Montauk 17. I currently have a 1993 mariner 115 and was thinking that a Yamaha 90 four would be perfect. Is that the consensus?
Could i go to a 115 4 stroke or is that too heavy?

Posted by Phil T on 01/13/24 - 5:11 PM

Figure out the difference in weight between the Mariner and the 115hp. Add it to the splashwell (ready mix concrete bag).

Test the boat handling.

If you move the battery to the console, the 115hp will be fine. Very fast with a WOT of 49 mph if 3 holes up and a good stainless prop.

Posted by Dsmith181 on 01/17/24 - 4:29 PM

Phil T wrote:
Figure out the difference in weight between the Mariner and the 115hp. Add it to the splashwell (ready mix concrete bag).

Test the boat handling.

If you move the battery to the console, the 115hp will be fine. Very fast with a WOT of 49 mph if 3 holes up and a good stainless prop.

Thanks Was planning moving the batteries there anyway

Posted by Finnegan on 01/17/24 - 8:30 PM

Your existing Mercury/Mariner 115 weighs 356 lb. Mercury's four stroke 90, 115 and 115 ProXS all weigh 3 lbs more, at 359 lbs. So at least a Mercury 4 stroke has no weight consequences. Nor would you need to move battery to the console, something I would never do on my 115HP powered Montauk.

Since your boat is already Mercury powered, you should seriously consider staying with Merc and greatly reducing installation costs, as everything you have is compatible and can be re-used. Additionally, the Mercs weigh less than Yamahas and have bigger displacement, and probably are faster per HP.

There is an Instagram video showing a Whaler Newport powered with a Merc 115 ProXS literally blowing the doors off a Montauk powered with a 115 Yamaha. If it were me, I would go with the ProXS. Great cowling graphics also, with silver gear case!

Edited by Finnegan on 01/20/24 - 10:39 PM

Posted by Dsmith181 on 02/02/24 - 7:19 PM

Finnegan wrote:
Your existing Mercury/Mariner 115 weighs 356 lb. Mercury's four stroke 90, 115 and 115 ProXS all weigh 3 lbs more, at 359 lbs. So at least a Mercury 4 stroke has no weight consequences. Nor would you need to move battery to the console, something I would never do on my 115HP powered Montauk.

Since your boat is already Mercury powered, you should seriously consider staying with Merc and greatly reducing installation costs, as everything you have is compatible and can be re-used. Additionally, the Mercs weigh less than Yamahas and have bigger displacement, and probably are faster per HP.

There is an Instagram video showing a Whaler Newport powered with a Merc 115 ProXS literally blowing the doors off a Montauk powered with a 115 Yamaha. If it were me, I would go with the ProXS. Great cowling graphics also, with silver gear case!

Thanks!!! Great advice