Johnson Seahorse 10hp

[jroberts24]

I have recently purchased an old Johnson Seahorse 10hp from an elderly lady down the road. She claims that she never remembers her late husband ever using it. From looking at the prop and the motor, I would say there is not more than 5 hours on it. The model is QD-16, but there is no year written on it. I cleaned the carburator and changed the plugs. The dang thing fired right up. The problem is that I don't have a book on this motor. Also, I don't know much about changing the leaness or richness of the fuel. What should I run it at? Another thing, the directions on the decal located on the top of the calender says to use 16:1 fuel mix. Is this a bit much? It smokes like crazy while I am running it.

 

[rickdb1boat]

Re: Johnson Seahorse 10hp

jroberts24 <br /><br />QD-16 is a 10HP 1955 <br />16:1 Mix is correct. It will smoke quite a bit at idle, especially if it has not been run in a while. Also, change out the water pump before you run it again, as it is unknown when the last time it was done. As for the mixture, lightly seat the mixture screw and then back it out 1 1/4 turns to start with until you find the best setting.<br /><br /> manual

 

[alcan]

Re: Johnson Seahorse 10hp

Hi J Roberts<br /> The proper fuel/oil ratio for your QD is 24/25:1. 1 quart of outboard oil to six gals of gas. Back in the day when these motors were new and you had a problem obtaining outboard oil, You could subsitute SAE 30wt nondetergent motor oil at the higher ratio of 16:1 (in a pinch). If you would like a copy of an owners manual, post your e-mail address and I'll try to send one. With proper mix and carb adjustment you will get a little more smoke than a modern motor. It should how ever be barely noticeable.