Johnson Choke Solinoid Problem

zshuff

Cadet
Joined
Jun 30, 2013
Messages
15
Hello all,
I've got a 74 Johnson 50hp that had some idle problems so I disassembled carbs and thoroughly cleaned them. They had been rebuilt within the past couple years so the floats, needles and gaskets were not in need of being replaced. Once I had reassembled everything my motor would not start. I've got the needles set to factory specs. (One full turn open on the top, and a turn and a half open on the bottom). I noticed that the primer solinoid was not working in shutting the choke butterflies within the carb. However, as far as I know it's never worked and I could still get it to start. Now it doesn't want to start at all. Also when I go to crank it it seems like alot of gas is flooding out of the front of the carbs. I figured this was normal as the gas has nowhere to go if the motor doesn't start. What are y'all's take on my situation? I know my starter solinoid is good because the motor is getting power to crank but my choke doesn't seem to be working at all. The manual choke from the controls pushes down on my throttle a tiny bit but that's the only action I'm seeing. Thanks for your help!
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Johnson Choke Solinoid Problem

Assuming that you have checked and the engine has proper compression and spark...............

Fuel flows out of the carburetor only if a problem exists with the float needle valve, the float is not adjusted properly, or the float chamber air vent is clogged/plugged. The suction of the pistons in the up mode draws the fuel inwards regardless of whether the engine is running or not.

(Carburetor Float Setting)
(J. Reeves)

With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.

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Proper carburetor adjustment follows:

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Note 1: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.

Note 2: If the engine should be a three (3) cylinder engine with three (3) carburetors, start the adjustment sequence with the center carburetor.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

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Check for voltage at the electric choke solenoid when the choke switch is engaged. If a full 12v exists, then no doubt the solenoid is faulty. If no voltage, find out why and correct it.

Are you saying that the manual choke lever does not cause the choke butterfly to close? If so, what is stopping the choke butterfly from moving?
 

zshuff

Cadet
Joined
Jun 30, 2013
Messages
15
Re: Johnson Choke Solinoid Problem

Yes I have good compression and spark. This is for sure a gas related problem. I will take apart carbs again today just to make double sure I assembled them correctly. Yes the manual choke is not closing the butterflies. The solinoid doesn't close them at all (this is why I believe the solinoid may be bad). It's almost as if its missing a peice in the choke relay that would allow the choke to function and close off the air.
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Johnson Choke Solinoid Problem

Unfortunately I'm not there to spot the choke problem solution. If the manual choke lever doesn't close the butterfly, then something is either missing or improperly adjusted. I can only wish you luck with that.
 

zshuff

Cadet
Joined
Jun 30, 2013
Messages
15
Re: Johnson Choke Solinoid Problem

Yea thanks. I may have to end up taking it too my mechanic as I don't know which peice I could be missing.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,589
Re: Johnson Choke Solinoid Problem

You could always look on here at the parts breakdown for your engine and see what is missing and/or how the carb and choke are assembled correctly... I have a '76 40HP Johnson myself and just last week rebuilt that carb and can tell you that both the electric solenoid AND the manual choke linkages are working absolutely perfect...
 
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