1969 20hp. johnson o/b motor.

[ricbov]

Hi, I have a 14ft. closed bow boat with a johnson 20hp. o/b motor--manual start, the boat is a Wa/Woo 1969 fiberglass. The boat will not plane even at full speed. I had the motor rebuilt in July 2004 it runs great but seems underpowered. There is no tag on the boat that tells Max. hp. I can go to. I fish a small Lake here In Ithaca,Ny. but do not want to take it on Cayauga Lake because it is very slow.Could I go to a 30hp motor safely or how do I find out?

 

[STEVEHONAS]

Re: 1969 20hp. johnson o/b motor.

I have a 15foot glass closed bow with a 85 hp it flies so i think a 30-40hp would be safe

 

[R.Johnson]

Re: 1969 20hp. johnson o/b motor.

You don't say what your boat weighs. When you say closed bow, do you mean a boat such as a runabout that would have forward steering? This kind of boat can get right up there in weight. A 20 HP should at least get up on plane. Can you give usmore information?

 

[ricbov]

Re: 1969 20hp. johnson o/b motor.

Sorry, yes it has forward steering and controls. I dont have a weight on it. The top or bow part of the boat is wood and fiberglass the hull is all fiberglass. It is heavy my problem is I cant find out what is a safe motor for the transom. The boat was made by the Harwill Co. in Michigan which was the parent company of Aerocraft they ended business in 1978 they made some runabouts but never caught on. I think it's to heavy for the motor but I dont have a manual.

 

[silenscurator]

Re: 1969 20hp. johnson o/b motor.

Although I don't have the same type of boat as you, most of the tags that are attached that rate HP, weight empty, Max weight and load are attached at factory, but are issued by the US Coast Guard. Even in Canada, our boats, or at least mine comes with that tag on it. Try contacting the US Coast Guard, they may have the guidelines and the like for your boat.

 

[steviecops]

Re: 1969 20hp. johnson o/b motor.

Is it a planing hull or displacement? If it's a displacement hull, it won't plane at any speed.

 

[ricbov]

Re: 1969 20hp. johnson o/b motor.

Steviecops, how can I tell? I'am new at boats the marine shop I had the motor rebuilt at said it should plane.I know it is sloppy under power before this boat I had a 14ft fiberglass open bow with a 10hp. gamefisher o/b and it seemed to do alot better. My only concern is in a bigger Lake I would have to stay close to shore for safty reasons. The other boat I mentioned was a Tri-Hull and seemed alot faster. The only tag on the boat I have now just gives the serial number.

 

[steviecops]

Re: 1969 20hp. johnson o/b motor.

Planing hulls are generally flat or flatish bottom boats. They can be deep or medium V, or like your old boat, a tri-hull. Usually they flatten out towards the back end.<br /><br />Displacement hulls are usually the traditional looking boats. Round bilge with a keel. If yours is a displacement hull, don't think you'll have to stay close to the beach due to lack of speed! Displacement hulls are very safe in rough conditions. It'll take you longer to get back, but you'll get back every time.<br /><br />Planing hulls get up and skim over the water, whilst displacement hulls sit deep and push the water out of the way.<br /><br />Can you post a photo of your boat? Then we could tell you what you have and what to expect in the way of performance.

 

[jfm1]

Re: 1969 20hp. johnson o/b motor.

Brandy Wine I have a 1969 14ft fiberglass with a 1967 20hp johnson it takes a long time to plane out, my boats rated for a 50hp But most of the lakes around here are 10-20hp max. As long as it gets me to the fish it's all that matters.

 

[Solittle]

Re: 1969 20hp. johnson o/b motor.

BW - Before plunking down money for another motor you need to find out of your 20 is running right, has the correct prop and mounted correctly. Look for condition and pitch of the prop, location of the cavitation plate relative to the bottom of the hull and tune of the motor. A 20 should plane a 14' boat if set-up correctly.

 

[ricbov]

Re: 1969 20hp. johnson o/b motor.

Thanks to all of you for your help.I will look into the motor more and see if everything is set right.One guy said it best "It gets me to the fish and back" Thanks again.