48HP Evinrude

[MichaelMullis]

I have been looking at some older pontoons and one that I looked at the owner told me that I had to very gradualy add throttle to increase speed or the "clutch" would slip. I never knew outboards had "clutches". Is this true? What else could be causing this problem. He told me that if throttle was increased to fast the motor would rev up but the boat would not gain speed. Sounds to me like it may be a case of prop slipping on shaft. Any ideas? This motor is a 1989 48HP Evinrude on a 28' Harris pontoon. Any info would be helpfull.Is there a simple formula for coming up with a Max. HP rating for pontoons.

 

[WillyBWright]

Re: 48HP Evinrude

There should be a capacity tag somewhere on the boat. If it's missing, you can usually find that information on one of the BlueBook sites like NADA. On a 28' it's going to be a wole lot more than 48Hp. In my opinion, more than 100 Hp would be a waste. In general I like 50s on 20', 70s on 24', and up to 100 on 28'. If you want to do any waterskiing or tubing behind it, max it out.<br /><br />There is a rubber hub in the propeller that could be slipping. It's usually easy to see if it's slipping. Take the prop off and look at where the splined washer under the nut and the thrust washer on the other end contact the prop. If the surfaces are shiny and worn, then that's the problem. Props can be rehubbed. It is always a good idea to have a spare prop, so this would be an excellent time to invest in one. If the problem goes away with the new prop, send the old one out for rehubbing and keep it as a spare.<br /><br />It is also possible that the motor is just sucking air if you take off fast. Have somebody drive the boat as you watch the motor in the water. If it's sucking air, you can feel, see, and hear it.

 

[rickdb1boat]

Re: 48HP Evinrude

I agree with Willy. A 48 HP is way underpowered for that big of toon. It will move it, but very slowly. It will also work the engine to an early death trying. I have a 24' toon that has a 70 HP rude on the back and it gets me 24 MPH, with fairly quick take-off. I can get a light skier up with some effort and tubing is easy. I also know someone who has a 28'er and he has a 150 on his and it zips across the water about 30 MPH with a few people on board. The problem with the large toon is you need the extra power to move the thing when you are loaded down with a lot of people, little lone the length of the boat itself. The point is, as Willy said, get at least 100 HP for that big of toon and you will not regret it. You should have no problem at all putting a 150 HP on there and be legal, as well as happy, if the wallet allows...<br /><br />BTW- Harris makes a fine pontoon boat. Even the older ones. Been around along time.. Also, with that small of motor on there, I would expect more spun hubs in the prop do to the load it has to push.