Motor weight q's

[twintrades]

I have a Jhonson 50 hp and would like to know the weight of it. Im thinking about switching motors on my boat. From a 40 hp older one (60's) to the newer ( i think) 80's one.

Model 50esl71s

The boats only rated for a 40 hp. Would 10 hp more be to much for it? Its a late 50's sport lido we use for tubing (hopefully skiing) . I dont want to wreck the boat or have the transom be ripped on.( or off for that matter)

As of right now getting in the boat takes one person on one side and the other across from them climbs in the the boat from the water. ( It gets scarry close to the waters surface if both of them are on the same side)

What do you think??

 

[steelespike]

Re: Motor weight q's

The 40 could be as little as 135 lbs and up to about 170.the 50 197 to 218.
I think between the weight and power your asking for trouble.
You could fine tune the 40 setup.Careful setup and prop selection could improve things a lot.

 

[twintrades]

Re: Motor weight q's

On the 40 i have a 13 pitch prop book says its good for skiing. But cant get me outa the water. what else could i do to tune the engine??

 

[jdsgrog]

Re: Motor weight q's

I actually have a glasspar lido with a '67 johnson 33hp. The motor is about 130 pounds. At one point I rigged the boat with two batteries and a transom mount trolling motor. With both batteries in the rear, the boat's transom was pretty low. It was fine in calm water, but when it got a little choppy and the boat was sitting still, water was coming over the transom. So assuming the 50 is about 200 pounds or more, you may get the same problem.

As for tuning the 40, you can try to find a lower pitch prop and it may get a skier up. I found a four blade propeller (model AMC-444) made for 60's motors. From my understanding, it was made for motors in the 25-40 hp range. I haven't been able to use it this season as I've been having some motor issues, but supposedly, it will get better hole shot which is good for towing. The blade is a 10 inch diameter 11 pitch prop.