Re-power of project

[Wallman67]

I know I'm only half way into my restore, but waiting for an end of the cold weather before I can resume re-building I've been searching for a new outboard. I want a 4-stroke.

Here's what I'm rebuilding. 1976 17 foot T-166 Glastron Sportster XL tri-hull. The Hull rating is 100 HP.

Here's what I know...
My current 1976 85 HP 2-stoke Mercury weighs approx 250 lbs.
A 1976 100 HP 2-stroke Mercury weighs appox 300 lbs
A 2010 50 HP 4-stroke Mercury weighs appox 265 lbs.
A 2010 75 HP 4-stroke Mercuy weighs appox 399 lbs.

Is the hull rating a HP rating, a weight rating, or a combo of both ?

I want the 75 HP but a little worried about the extra weight. I am rebuilding the transom and can beef it up a little ????

 

[Jeep Man]

Re: Re-power of project

The weight isn't the issue. Your craft will sit a little lower that's all. The rating has more to do with the thrust the motor creates. Good luck with the re-build.

 

[Bondo]

Re: Re-power of project

Is the hull rating a HP rating, a weight rating, or a combo of both ?

Ayuh,... It's rated for the Hp, but Weight still needs to be taken into consideration....

You don't want waves lappin' over the motorwell....

 

[barbosam]

Re: Re-power of project

I think the weight could be an issue as bondo says you don't want waves coming over the transom; not to mention the boat will be off balance and the performance could actually suffer, Personaly I think the 100lb difference is a lot.

One thing that cn be done to offset the weight is to move the batteries up forward. If you move two 40lb batteries to the front of the boat then your really only throwing the boat off balance by 20lbs, no biggie. Of course you will have to use some heavy gauge cable to avoid voltage drop across the longer battery cable run. I typically use 2 gauge wire for a run this distance.

Off course you could always use an Etech instead of the Merc, and problem solved
75hp and only 320lbs. you can even step up to 90hp for the same weight.