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Swapped out a Onan for a Kohler on a 516. no kill switch

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The Onan 16 hp gave up so I installed a Kohler M16 . The problem is there is no way to kill the engine when I turn the key. The Kohler has a harness plug for plug and go with 4 wires, Violet, white and 2 black wires. I know what the wires are for, but I don't know how or if it's possible to shut down the motor with the WH key switch. There are 5 terminals on the key switch, B, S, I, A and R. I read how the continuity ( start, B, S, I and R   run, B, I, A and R ) flows between the positions but there is no mention of a ground. R is not used, but is energized in both positions. I think I might have to install a separate switch for kill, but I am hesitant because I might leave the key switch in the run which will do damage to the engine's electrical (I think). Any suggestions?

Thanks for you input




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The Onan ignition is powered by the battery.

The M16 ignition system is self-powered and the single ignition wire is simply grounded to the chassis to shut the engine off. Do not allow any battery power into the ignition wire as that wire burn up the ignition coil.


Post the spec number off the M16 engine so we can determine what size of charging stator it has.

Also post the tractor model and serial number so we can see what you started out with. If you don't have those post the numbers off the Onan engine.


Changing to the correct ignition switch plus possibly reconfiguring the seat switch wiring should get you going.




Guessing this is what you have with a 20 amp charging system.

and want to get to this with a 15 amp charging system. 


Uses 111215 replaced by103991 5-terminal 3-position ignition switch for magneto ignition. There may be a 6th terminal to ground the body of the switch.

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Adding a momentary contact push-button switch (like a starter push button) will work as a kill switch.

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The correct ignition switch is cheap and the right way to do it.


A great majority of lawn tractors with briggs engines use the switch you need.



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Here are the numbers you asked for:

Kohler M16

spec. 711523


3G 1710538B

serial AB 83314768

Wheel Horse 516

serial 31160E01  11418


The only power going to the engine is to the starter via solenoid. I do have the rectifier (B position) wire (violet) going back to the battery to charge. The fuel gauge is still reading after all night being off. Is that normal? All the safetys have been eliminated. I was thinking about using a n.o., n.c. relay to wire from the ignition wire for a kill switch.



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The wiring diagrams are correct for the tractor and the engine you are using.


The relay is a good idea. Wire the engine ignition wire to the normally closed contacts with one grounded to the chassis and have the ignition wire from the switch power the relay coil to open the contacts to run. Wheel Horse actually did this in the early-mid 1980's.


Pink wire from the ignition switch accessory terminal powers the gauges so the fuel gauge should be off when the key is off. The headlights are also powered by the A terminal - will they work with the ignition key off?



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