88 Johnson GT 150 WONT SHUT OFF/HELP!!

[87Chap]

i put my boat on the trailer the today and turned the key off and my motor would not shut off and i have no idea what would cause this. it has never done this before and i had turned it off and on all day long and this occured the last time of the day when i really needed it to shut off

i had to clamp the fuel line to get the engine to finally shut off

any help would be great! thanks

 

[crxess]

Re: 88 Johnson GT 150 WONT SHUT OFF/HELP!!

First, Never Ever Starve the motor to shut down. You can cause serious internal damage from leaning out.

Either choke it to flood/stall or cover the air inlets on the carb.

Sounds like your switch may be dirty. switch normally shorts ignition to ground when turned off. Could also be a loose wire or corroded connector somewhere between. key and motor.

 

[jonesg]

Re: 88 Johnson GT 150 WONT SHUT OFF/HELP!!

they can run even with the red plug disconnected,
even with the battery disconnected,
decarb it.

 

[87Chap]

Re: 88 Johnson GT 150 WONT SHUT OFF/HELP!!

what do you mean by decarb it?

 

[lindy46]

Re: 88 Johnson GT 150 WONT SHUT OFF/HELP!!

I would suspect a bad ignition switch or bad kill switch (if so equipped) or a loose/broken wire.

 

[cdoliver]

Re: 88 Johnson GT 150 WONT SHUT OFF/HELP!!

they can run even with the red plug disconnected,
even with the battery disconnected,
decarb it.

I hardly think decarbing will cure this problem...as already stated, problem most likely your key switch or connections on the switch or a problem with the ground at the key switch.

 

[emdsapmgr]

Re: 88 Johnson GT 150 WONT SHUT OFF/HELP!!

I have seen this somewhat rare situation on a twin power pack V6, (like yours) where one pack was defective and would not respond to the ground from the key switch. When shut off, only one pack was grounded-the engine dropped an rpm or two and kept running on the other pack. Turn the key back on and the engine picked up a few rpm. Solution: replaced the pack.