1958 Johnson 10 hp stalling at idle

[putvalley1003]

I have a 58 Johnson 10 HP which I am having trouble keeping it running at idle it runs good when throttle is at start and when I am running the motor, only when I bring throttle all the way down to shift it stalls. I noticed the other day that when I prime my fuel line if i don't start the motor right away it gives me trouble starting could an air leak possibly in the fuel tank be my issue? My thought's were because there is no fuel pump and the motor is pressurizing the tank to send fuel to carburetor maybe at low idle the pressure the motor is putting in the fuel tank is to low to pump fuel up to my carburetor which is stalling it out? Thank you in advance for any advice and input!

 

[flyingscott]

Do you know that turning the throttle down is how you shut those motors down? Can you idle it low enough to shift and troll along?

 

[F_R]

Have you checked the coils? All 1958 Johnson twins have bad coils unless they have already been replaced. You are wasting your time until you do.

Once the tank is pressurized, it should hold pressure to run at any speed all day long. Or till you run out of gas, whichever comes first.

 

[putvalley1003]

I did not know that sorry I am new to these older outboards and am learning as I go. I do know that I have a black kill switch just below the throttle I thought that was the only proper way to shut the motor off, when I shift into forward I have to have it revved up a little more then I would think necessary which causes a harder shift. My throttle has printed on it start which I cant go past when in neutral and after I let it warm up I cant lower the throttle to where it says shift and if i'm not careful it will stall out like it doesn't want to idle at lower speeds when trolling along it starts to sputter out like its not getting enough fuel. I am still using the original gas tank that to my knowledge has never had gaskets changed on it and if I prime the tank if i'm not fast enough I within 30 sec. in needs to be primed again is that normal to? or should the tank hold a prime?

 

[putvalley1003]

I will check the coils tomorrow I just bought this motor a couple of weeks ago and was told they were replaced but I will check myself Thank You!

 

[flyingscott]

Have you tried adjusting the low speed needle?

 

[F_R]

Do you understand how the tank primer works? Contrary to popular thinking, the primer does not pressurize the tank. What it does do is pump fuel into the carburetor so the motor can be started. Once the motor is running, the motor pumps air into the tank to pressurize it so it continues to feed fuel to the carburetor. Also, the need to start the motor within 30 seconds makes little sense. The carburetor is similar to a little bowl of fuel just sitting there waiting for you to do something. Unless of course it is overflowing or something.

BTW, the slow-start-fast wording on the throttle dial is seldom accurate, more just a guide.

 

[racerone]

Had to coach a fellow the other day about how the tank is pressurized once the motor starts.----Primer just fills the carburetor ready for the " Armstrong " starter..

 

[lindy46]

You can turn up the idle adjustment screw on the port side of the motor to keep it idling faster. Then use the kill switch to stop the motor.