Re Power Question

[LuckyGia]

I am considering re powering my boat. It is a 2009 Smokercraft 171 pro bass. Rated for up to 90hp. I currently have a 60hp Yamaha on there now.

My question is the boat rating based on weight of the motor, or power and torque of the motor ?

If it is weight, I could easily justify a 115 hp as the weight is very close.

Any thoughts ?

[BaitMonkey1984]

I always was of the belief that the reason their was engine ratings was due to structural integrity of the boat as well as issues with how the boat would perform with a specific engine HP. I would therefore be afraid the higher HP motor would rip your transom off, or cause your boat to operate in a haphazardly manner injuring, killing, or just plain ruining your day. I try to tweak everything-this is not something I even think twice about modifying. It is there for a reason. 

[slonezp]

You will have a hard time finding insurance and if you were involved in an accident you would surely be the negligent party

[LuckyGia]

Well that all seems likely correct. I will stay with a 90. Is the 4 or 2 stroke a better option ?

[Fishing Rhino]

I'd go with the four stroke.  Much quieter.  If you like the sound of power, go with a two stroke.

 

My buddy had an aluminum boat with a four stroke on the back.  Except for passing through the air, it was like being in an automobile.

[WIGuide]

I think the rating process has a few factors that go into it. I'm not sure what's all entailed with it though. Being that the 90 and 115 are usually built on the same block there's structural integrity will be ample enough for either. Your only drawback of over rating it would be trying to get insurance on it (if you keep insurance on it) or if you fish in tournaments. 2 stroke vs. 4 stroke is still a debate. 4 strokes are quieter and cleaner burning, but 2 strokes are lighter and getting pretty clean burning too. 

[junyer357]

I wouldnt go over the rared spec. Its my understanding as well it is based on the specs, rating, and engineering of the hull and transom, not weight of motor.

Rumor is among the fishing community around my area is that they are phasing out all 2 stroke motors in the near future industry wide. I know its already becoming harder to find bulk oil for older motors like ours.

[LuckyGia]

I didn't think about the insurance issue. For that reason alone I will reluctantly stay within the manufacturer parameters.

I was only thinking about the weight being equal for both.

Thanks for the input.

Now to find a dealer that will offer me what my trade in is worth.

I have researched what my motors value is, how close to that should I expect to get ?

2008 Yamaha f60 4 stroke.

[SoFlaBassAddict]

If I were repowering, I'd definitely be looking at a 4 stroke. But man, I just love the sound a 2 stroke makes.

On my offshore boat, I'd kill to have a new four stroke. That monstrous motor is so loud it's not even funny. You can forget about speaking to somebody when moving at cruising speed.

[LuckyGia]

I was just wondering about speed difference between the two stroke and 4 stroke. With the 2 being lighter was curious if the 2 would be faster.