1955 Johnson Seahorse

[jroberts24]

I have a 1955 Johnson seahorse that will fire right up but won't stay running very long. I cleaned the carburator but did not mess with anything. It has new spark plugs. I don't know how to set the lean/rich valve, but I put them all the way in and backed them out 1 1/4 turns out. Any input would be much appreciated, as I do not know much about 2 cycle engines.<br /><br />Thanks

 

[JB]

Re: 1955 Johnson Seahorse

Howdy, JRoberts.<br /><br />Johnson made several SeaHorses in 1955. Which one do you have?<br /><br />Do you still have the pressure tank (twin hoses) or does it have a fuel pump?<br /><br />Let us know.

 

[Chinewalker]

Re: 1955 Johnson Seahorse

When you say you "cleaned the carb" did you take it off the motor and disassemble it or just spray some carb cleaner down the throat? A proper carb cleaning means a complete disassembly, liberal use of carb cleaner and compressed air, and proper setting of the carb float (dead on level when the carb body is upside down).<br />- Scott

 

[jroberts24]

Re: 1955 Johnson Seahorse

JB,<br /><br />I have the one with the pressure tank, model QD-16. I have taken the carb off and every thing looks and works fine. The sediment bowl is filling and the engine is firing up fine. The needle valve is also fine and the float floats. The carb is spotless.<br /><br />jroberts

 

[rolmops]

Re: 1955 Johnson Seahorse

Turn the upper needle valve(low speed) 2 full turns out. The lower one(this is the high speed)should go 3/4 turns out.Take it out on the water and with the engine in gear at minimal speed start closing the valve until you have the highest rpm point.Then turn it a quarter turn back out.Next go full speed and start closing your high speed valve until you get the highest rpm,then open that back up a touch.Last redo your lowspeed.You should be all set.

 

[JB]

Re: 1955 Johnson Seahorse

Howdy, JRoberts.<br /><br />Okay. A QD-16 is a 10 hp.<br /><br />On the tank there is a plunger to prime the engine. What happens if you pump that when the engine tries to die?<br /><br />I think your engine is "running out" of fuel. In that system it could be an air leak in the tank or pressure hose from the engine, or a bad check valve (that holds tank pressure).<br /><br />Finally, and most common, is a failed "O" ring in the fuel line connector, either at the engine or at the tank.<br /><br />Let us know what you find.

 

[jroberts24]

Re: 1955 Johnson Seahorse

JB,<br /><br />Thanks for the help. The engine still dies if I pump it when it is trying to die. With the manafold off, there is a little gas in the carb by the choke valve. There doesnt seem to be an air leak unless it is not noticable. It will crank and run wonderful for about 2 seconds, then dies. It will continue to start for about the next 2-3 pulls, but if continued will not. If I let it sit for a couple minutes, it will start wonderful again. There was a little fuel leaking from the fuel line connector, but I put a cable wrap on it to make sure it didn't leak or suck air. At my level of knowledge about the subject, I don't know what else to do.<br /><br />Thanks,<br />jroberts24

 

[Yepblaze]

Re: 1955 Johnson Seahorse

Being as it may not have a kill switch and rely on the throttle to settle itself in the off position,<br /><br />Have you tried to maintain the engine with the throttle grip, or is this a hands off issue?

 

[alcan]

Re: 1955 Johnson Seahorse

Hi Jroberts<br />The zip-tie thing won't cut it. If you have a fuel leak at the connector then you more than likly have a air leak also. The good news is the connectors can be rebuilt (replace the o-rings. Do not discard the connector they are getting hard to come by. For testing purposes hook up the fuel hose directly to the motor. The fuel side to the carb and the air side to the block. This will tempoarly by-pass the connection. Make sure your tank builds and holds presure. Check the cap gasket for cracks and splits. When you loosen the cap after running it should swoosh or what ever sound you like, (release presure). It sounds to me like your motor is running out of fuel. May the filter is pluged a little. Any leaks in this type fuel system and it won't work.

 

[jroberts24]

Re: 1955 Johnson Seahorse

I am going to try the fuel line direct to the engine bypassing the connection, but if that is not it, what could be the problem? Also, how do you rebuild those double connectors for the pressurized tank systems?<br /><br />Thanks,<br /><br />jroberts

 

[alcan]

Re: 1955 Johnson Seahorse

Hi Jroberts<br />This is easier do do than explain. You need to find a long skinny punch. You may have to make one up. You just place the punch in the hose end of the connector and tap out the brass/bronze innerds,for each side. There will be a plunger/stopper, a spring and a bushing w/o-ring. Replace o-rings,dab a small amount of gasket goo on the bushing and reasemble. A lot of the Pros. have a little jig (speical tool)for this job. It holds the connector and catches the innerds. I made one up with a small block of wood. You may want to use a socket or somthing simular during disassembly to catch the parts. You will also need the right o-rings. I have tried several differnt places to get them, but have yet to find ones that will work. So you may need to find an OMC dealer to get the O-rings. Get some spares while your at it. My expirence has been that this connector is one of the main reasons folks have problems with motors of this era ( all motors in fact). How many times do you see guys carring their fuel can up the dock or beach dragging the hose behind them? Or disconnect the hose and drop it in the bilge. Make sure the male end (motor end)is in good shape also (no burrs). A good working tank and hose is worth more nowdays than the motors they run. As I can't see your stuff its hard for me to say, but you might consider just over hauling the whole fuel system, tank and all.