IS 150HP Johnson too much for my boat??? Should i be looking at a 90 or 115?

[zarillus]

Long time since i have been here.I am wrapping up my boat project and i am getting ready to buy a motor and saw a good deal on a 93 Johnson 150 HP motor.My boat is a 67 Larson all-american 166 16ft boat.I am not sure what the max hp is however my new transom is nearly two and 1/2 inches thick with knee braces.So i am not worried about the transom holding the motor.
My Questions below:

How much gas would this beast use I do have an 18 gallon tank?
How much weight is this going to add as compared to the 67 Evinrude Fat 4 dockbuster 85 hp that was on it?
Where could i get specs for Max Hp for my boat?

 

[reddogg]

Re: IS 150HP Johnson too much for my boat??? Should i be looking at a 90 or 115?

I'd think it's to big for the boat. Older Johnson/Evinrudes are known as good motors but they do suck the gas, I had a 150 that would drain a 13 gal tank in 30 min running at full speed. It's going to add more weight as it's a V6 and a much bigger engine. Do a search with your boats make, you should get an idea of what size motor they usually use.

red

 

[guitarkev77]

Re: IS 150HP Johnson too much for my boat??? Should i be looking at a 90 or 115?

You can use the Coast Guard formula for calculating max H.P. for an outboard equipped boat.

I believe that it is:
((Length of boat) x (beam) x 2) -90. So, for example, a 16 foot boat with a 6 foot beam would be (16 x 6 x 2) - 90 = 102 HP.

So a 100 HP motor would be fine for this size boat. This is a very generalized formula and is only applicable to outboard equipped boats, not I/O.

Hope this helps.

 

[Cadwelder]

Re: IS 150HP Johnson too much for my boat??? Should i be looking at a 90 or 115?

Well to start with all 2 stroke outboards suck gasoline, they are not know for fuel economy, so if gasoline consumption is a big concern I'd recommend paddles. Just joking about the paddles of course, but I think you see my point.

As far as the 150, yeah it does sound a big large. The strength of the transom isn't the only question that comes into play. A boats hull is designed for a max speed and performance, going way over the max can result in unsafe top end speeds. I'm not saying your hull won't handle the 150, but I personally would not recommend it.

Happy Boating.

 

[zarillus]

Re: IS 150HP Johnson too much for my boat??? Should i be looking at a 90 or 115?

Thanks guys i found out the Max hp is 100HP

 

[emoney]

Re: IS 150HP Johnson too much for my boat??? Should i be looking at a 90 or 115?

It's probably a good idea to find an older CG plate or have a printer make you one. Get the wrong water patrolman stopping you and they'll give you grief over not having one.