fuel conversion for QD-16 1955 Johnson 10hp

[jroberts24]

I am currently converting my old Johnson seahorse 10hp (QD-16 10hp) from a pressurized system to a modern system. I am wondering if anyone has any input on the subject. Briggs and straton make a bolt on diaphram fuel pump for small engines (size is about 2X2inches) 1/4 inch ports, that runs off of air pulses from the engine. Would this work for my fuel conversion if I hooked the air line that would normally pressurize my tank to it. Also thank all of you that have been a great help to me the past month on restoring this vintage motor to top working condition.<br /><br />thanks,<br /><br />jroberts

 

[Yepblaze]

Re: fuel conversion for QD-16 1955 Johnson 10hp

B&S, mikuni, and many other pumps out there will work fine.<br /><br />All you need is a good crankcase port location that will provide the negative and positive pulses. <br /><br />I'm not sure if the port used for pressurising the tank provides the osilations needed.<br /><br />Other than that there might also be a different needle/seat assy required in the carb due to the increased fuel pressures.

 

[bowhuntrrl]

Re: fuel conversion for QD-16 1955 Johnson 10hp

I've done several of these conversions. We usually use a fuel pump from a later model(60's) engine that we've scavenged off a junk engine. We bolt this on to the block somewhere on the starboard side of the engine toward the back of the boat. Fuel line goes in to the pump, fuel comes out of the pump, and you can pick up your pulse for the pump from the block, possibly the line to the tank. As I recall, you can also drill a hole in the block near the pump. There's a raised boss where we drilled. Then we would epoxy in a brass fuel barb for the pulse line. You would also add a standard fuel line fitting to the cowl to use with your new fuel tank and hose.I'm not sure if your B&S pump will provide enough fuel volume. If you starve for fuel, you can toast the engine(fuel=lubrication). Hope this helps .<br /><br />bowhuntr

 

[jroberts24]

Re: fuel conversion for QD-16 1955 Johnson 10hp

The line that pressurizes the tank comes from the crank case, just behind the carb, at about 5 o'clock to the piston. On the back side of the piston. Does anyone think that will work for running the diaphram pump?<br /><br />thanks,<br /><br />jroberts

 

[Paul Moir]

Re: fuel conversion for QD-16 1955 Johnson 10hp

I belive their's a check valve behind that. If you could jam it open it would work...

 

[OldSmoky]

Re: fuel conversion for QD-16 1955 Johnson 10hp

Hello there! Completely new here. I recently inherited a 1955 Johnson 10 horse (QD-16) from my gradfather who passed away. It is in perfect shape and got it to fire for a second with a little gas in the plug. Cleaned and oiled ready to go.......but no tank. Im completely new to boating and got taken by an ebayer who said it was a 2 line pressurized tank (do your research next time... ) that i was buying. It is a vintage Johnson tank in amazing shape but it is only a single line. Question is I found a tank for sale on the side of the road (literally the guy had 3 old johnson tanks and one was a 2-line.....) and was wondering if buying this tank or converting would be the smarter thing to do. Let me know......gotta get this boat and motor in water....ANY help greatly apprecited!!!!

P.S. sorry for the long post :redface:

 

[freddyray21]

Re: fuel conversion for QD-16 1955 Johnson 10hp

old smoky start a new thread you will get a better answer. If you have a two line tank it will work. If not convert it.
There is a sticky on it and here is another link: http://www.outboard-boat-motor-repair.com/Johnson/Pressureized Fuel Tanks.htm

 

[OldSmoky]

Re: fuel conversion for QD-16 1955 Johnson 10hp

Hey Freddy! Just wanted to say thank you for the fast response!!!!! I will start a new thread right now!