New to me/First boat, HP rating?

[CDM88]

I was given my first boat. 1991 14ft Sears 61255 (Sea Nymph?) aluminum jon boat. It has a 15HP Gamefisher 2-stroke that I was able to get running fairly well. Looking to the near future, if I stick with this boat I may look into getting a newer 4cycle motor to replace it (a lot of parts for this motor are NLA). Can I go up to a 20 or 25hp or do I have to stick with a 15hp? Is there any negative to upgrading to a slightly higher HP??

 

[Bob_VT]

Is there a rating tag? Since it's a john boat I would venture to say that 15 is probably max. Look up the ratings in the link in my signature

 

[CDM88]

Thanks. No rating plate that i can find.

 

[roscoe]

more hp means more weight.

too much weight will upset the handling of the boat.

1436 is rated for 15 hp

1448 rated for 25 hp

 

[jebby]

keep in mind modern 4 strokes are much heavier than the older 2 strokes it was likely designed to use. I would think you are loading up the back of that little boat a lot going that big. a 15 should have tons of grunt for a 14 foot john..... I just sold my 14" v hull and it was matched perfectly with a 15hp merc

 

[Chris1956]

Jon boats are flat bottomed. They will therefore plane with minimal HP. They are also not real stable at speed.

KBB might have the max HP rating for your boat. I would not exceed it.

I had a 12 foot Jon, with a 7.5 HP motor. With just me in the boat, the bow would go up and the wind would hold it up. I was concerned she would flip over backwards.

 

[CDM88]

Copy that. Thanks for the suggestions. Ill stick with 15hp if i upgrade or try to match weight as i know some of the newer portable outboards are getting pretty lightweight from what ive seen.

 

[jebby]

put it this way, on my last boat (that 14 footer with the 15) when I went from the 2 stroke 10hp to the 4 strok 15 I doubled the weight of the motor.