Jon Boat Motor

[CJB]

I have a jon boat similar to Knobby, a 14 x 36, to which I added a raised deck and foot trolling motor which has worked fine. It is a 1974 Fisher with a 1972 20 HP Johnson. The motor is a long shaft on a 15" transom and it sprays a lot of water, I'm not sure if that is the reason. The boat is rated for max 20HP. I am considering replacing the motor with a new one. The new 15 HP are the same weight class. Would I lose a lot of speed if I downsized to a new 15 with the correct short shaft?

 

[rickdb1boat]

Re: Jon Boat Motor

CJB <br /><br />If anything, a NEW 15 HP motor with the correct shaft length, will improve the performance and handling of your boat, as well as help eliminate the splash problem, too. Reasons being, is that the older motors were rated at the flywheel for HP and the newer ones are rated at the prop. You would have at least as much power as before(Allowing for engine wear), along with the correct shaft length, to push you along with less drag and much more efficiently.

 

[DJ]

Re: Jon Boat Motor

CJB,<br /><br />I agree with: rickdb1boat.

 

[Solittle]

Re: Jon Boat Motor

CJB<br /><br />If your goal is to cut down on the spray I'm not sure that the shaft length is your problem. I would suggest that you borrow a short shaft 15 and try it befor turning your wallet upside down on a new one. <br /><br />I have a 12' skiff with a 9.9 Johnny long shaft and mine dosen't spray any more than I think a short shaft would.