Johnson 40 on a 1000 lbs boat?

[pizzafellow]

Hi all,
I have a 16 ft 1973 Mark Twain boat; it weighs about lbs 1000(max power 100 hp). I was given the boat with a 1963 Evinrude 75 hp Starflite which is frozen. That will be a project in the future to awaken it. But I have a 1976 Jonson 40 that I have been working on. Question:
Is 40 hp enough to push that boat with the correct prop?
Any input will be much appreciated.

 

[ledgefinder]

Re: Johnson 40 on a 1000 lbs boat?

You hit the nail on the head with "...if it's propped right".

I have a picture of my Dad skiiing, in 1960, behind a 18' Trojan cabin cruiser powered by a 25hp Johnson. I can remember when a 40hp was a BIG outboard. It all comes down to propping it so that the motor can get up into it's power range (4500 rpm).

 

[ledgefinder]

Hull should go about 25-30mph with that motor.

Hull should go about 25-30mph with that motor.

Rough guess. But with the right prop, it'll be plenty of motor.

 

[pizzafellow]

Re: Johnson 40 on a 1000 lbs boat?

Thankyou Ledgefinder, that's what I thought, I am going to check the prop size and pitch then follow the instructions of the service manual. Once I get the motor running good that is!! I still have some issues that I am posting on the appropriate thread. I appreciate your response.

 

[steelespike]

Re: Johnson 40 on a 1000 lbs boat?

70hp is closer to the minimum but it will push it and with careful setup and right prop will plane.Start loading in a bunch of people and it will bog down pretty quick.

 

[rolmops]

Re: Johnson 40 on a 1000 lbs boat?

Dependent on whether it is a deep V or a flat bottom you will see a marked difference in performance.With a flat bottom you will zoom along and it will bring it up on plane nicely.If your boat is a deep V the 40 will have a hard time getting it up on plane.

 

[pizzafellow]

Re: Johnson 40 on a 1000 lbs boat?

It is a trihull nice and smooth surface

 

[crb478]

Re: Johnson 40 on a 1000 lbs boat?

I doubt that you will be happy with the performance of the 40. Even if it will plane it will not have the type of speed and performance that you will likely want. If you have all of the controls it won't cost you anything to try it though.

 

[kenmyfam]

Re: Johnson 40 on a 1000 lbs boat?

Set up and loading is huge with that motor. A little low on power for that boat but should plane out if set up is spot on.
Good Luck and let us all know how you make out.

 

[tashasdaddy]

Re: Johnson 40 on a 1000 lbs boat?

it will get you there, just not fast, that is 40% of the rated HP.