Engine doesn't want to die.

[Vern]

I have a Cub Cadet GT2542 with a Kohler Command 20hp horizontal shaft Engine.
When I turn the engine off it sounds like 1 cylinder stops but the other keeps going for about 3 - 4 seconds.
It has been doing that for the last month or so.
Any suggestions as to why it does that?
Vern
[email protected]

 

[old]

One cylinder could have what are called hot spots which can be caused by carbon build up that stays hot so when you shut it down it tend to diesel. If one idles the engine down real low then shuts it off that can help. Or sometime helps is to mix 1 quart of ATF to 5 gal of gas and run that

 

[504]

I would add to replace both spark plugs, and go down one heat range.

 

[kencombs]

That engine should have a solenoid mounted on the carb that plugs the main jet when the key is turned off.

If it works as it should, no fuel is available to burn after the key is off

It is normally powered when the key is on,and when power is removed a spring closes it. I'd check that for function first thing.

 

[wore out]

(quoted from post at 17:35:19 01/15/21) I have a Cub Cadet GT2542 with a Kohler Command 20hp horizontal shaft Engine.
When I turn the engine off it sounds like 1 cylinder stops but the other keeps going for about 3 - 4 seconds.
It has been doing that for the last month or so.
Any suggestions as to why it does that?
Vern
[email protected]

That engine has two coils/ignition modules and both are connected to the "kill" terminal.

There MAY be a diode in each of those leads to prevent the coils/modules from affecting each other during operation.

If something has happened to one of the wires (or the diode, if used) that coil/module won't get shorted out and that cylinder will continue to fire for a short time 'til there's no more fuel 'cause the fuel solenoid has closed off the supply of fuel.

I encountered a similar situation a few years back with a B/S V-twin, mice had chewed off the "kill" wire from one of the coils.