Small outboards:designed to run continuously at W.O.T.?

[D.J. Diver]

I recently bought a new inflatable to replace my 1972 Avon.I have a 1958 Johnson 10 hp that I've been using for years that used to be my Grandfather's. It sat in storage in pristine condition for 30 years before I started using it. It has always run like a champ and been a great motor. I use it mainly for scuba diving so it's usually loaded somewhat heavy,especially if someone goes with me.So basically it's always run at W.O.T. Are small outboards designed to be used like this? I've never had any problems and I mix my gas and oil at 50:1. I'm shopping for a new motor and was thinking of getting a 15hp because 50% more power with no weight penalty sounds good. But loaded with two divers and their gear it might be working a 15 hp too hard. So I'm thinking of a 25 hp now.I.m debating between a Johnson and a Mercury and am having trouble deciding I'd appreceiate anyone's opinions,thoughts or input on any of this. Thanks

 

[Chinewalker]

Re: Small outboards:designed to run continuously at W.O.T.?

Hi D.J.,<br /> Yikes! Double up the oil on that old Johnson! Your motor has bronze babbit bearings that need the extra oil to keep working! <br /><br /> As for continuous WOT, that depends on a couple of things. It sounds like your motor is having to work pretty hard to keep the boat on plane, so you're not doing the motor any favors. Particularly one that old. I'd go for an 18-25hp, as it won't have to run its guts out to get you to the dive sites.<br /><br />I'd keep the old Johnson, though, as they are a great little motor, as you already noted. Your kids will thank you someday...<br />- Scott

 

[Fouled Plug]

Re: Small outboards:designed to run continuously at W.O.T.?

It's always best, in my opinion, to have surplus power as opposed to not enough. I like to run the motor at 3/4 with a full load aboard, and have the extra HP for a reserve. As for the Johnson/Merc question, I think they are both fine motors. The deciding factor should be warranty length, dealer support in your area, and co$t. Keep the vintage motor for putting around the lake! I have an old 1957 5 1/2 that I run at 50:1 (plus an extra splash for good luck) with TCW3 oil with good results. The modern oil seems to be fine with my motor, and since I troll on occasion with it any richer on the mix and it gunks up the plugs. If you plan on mostly going flat out, Chinewalker's advice may be the best bet.

 

[12Footer]

Re: Small outboards:designed to run continuously at W.O.T.?

What Chinewalker and Fould Plug said.<br />Outboards are designed to run (2cycle) at a higher RPM than a 4cycle. They tend to run best at 3/4 throttle,and gum-up at extended idle. If you like to troll a bunch, use a samller kicker(electric trollin motor or something), and use the bigger engine to run a higher speeds.<br />But no engine was designed to run WOT all the time.<br />My .02