Bench firing a Kohler M12

[Shuboxlover 479]

I want to start and run my M12 on my work bench.    There are currently no wires on the motor other than the 5 pin plug (2 reds, 1 purple,  1 white) Can someone  please tell me how to hook it up electrically?  Also,  which ignition switch do I use?   Will the one out of my 520-H work? 

 

Thanks!!!

[WVHillbilly520H 10,376]

I bought a 312-8 a little while back and this is how it came wired, hope this helps, not sure on the switch looks new, Jeff.

[pfrederi 18,108]

Bit of a guess here...I am thinking this is an unregulated 3 amp charging system   The two red wires are the oil level switch and not relevant to your test.  The purple and white are the mag kill and the stator charging output.  I would guess the white is the stator output, the purple the mag kill.   Do not let voltage get to either wire.  The engine will run with all wires disconnected.  Stopping it is the issue.  Grounding the purple should kill it.

 

Is there a apec# on this thing???

Edited March 24, 2018 by pfrederi

[19richie66 17,540]

Purple should be 12 volts to the rectifier/regulator if you have this type of charging system. White should be mag kill wire. I have ran mine on a bench with it hooked to nothing. 12v to the starter, white to shut it off. Here is a link to the manual, if you don’t already have it.

https://power.kohler.com/na-en/engines/manuals

 

Edited March 24, 2018 by 19richie66

[clueless 3,052]

On my 1988 312, M12 it has the 15amp charging system. Purple wire come off the middle of the regulator bolted right next to the carb, white wire is the kill wire. Please don't cross them. I'll try to get some pic later.

Yea, Rich, that's the one. 

Edited March 24, 2018 by clueless

[Shuboxlover 479]

So...

 

1).   Just the flywheel spinning creates the spark and timing? 

 

2).  Does it matter which key switch I use? 

 

3).  Anything else? 

[19richie66 17,540]

1- yes

2- yes (you need one with a case ground/ ground terminal for the white wire unless you hook up a push button or toggle switch to ground. You can run it without the purple wire hooked up but it will not charge a battery like if it’s wired into a tractor) 

3- 😁

Edited March 24, 2018 by 19richie66

[pfrederi 18,108]

For you bench test you do not need an ignition key.  It absolutely makes a difference which switch you use when you put it on tractor you need an magneto switch or you will have very expensive magic smoke from your magneto.

 

Just cranking her creates timed spark. 

 

To be sure about the wire colors what spec number is the motor  Rich and Chris have the diagram for a 15 amp system....if you have a 3 amp system it uses different colors see below.  Until we are sure do not apply any voltage to either wire

 

Edit  For some reason file will not upload but 3 amp  whilte is unregulated output Blue magneto kill

Edited March 24, 2018 by pfrederi

[19richie66 17,540]

Thats why I included the link to the manual. But yes, don’t apply any voltage till you figure out what charging system you have. 👍

[pfrederi 18,108]

Another diagram  note the colors are different. 

 

If there is a voltage regulator on the front of the air shroud check the color of the center wire  it should match one of the ones in your plug.  The other is eh Mag kill

Edited March 24, 2018 by pfrederi

[Shuboxlover 479]

If in fact the purple is the mag kill, all i need to do is ground it then to shut the motor off? 

Edited March 24, 2018 by Shuboxlover

[19richie66 17,540]

Yes. As soon as its started and you remove the battery from the equation, you should be good. Chances are if that plug is coming out of the motor and you do not have an external regulator, then the purple is your kill wire and white is accessories as pfrederi’s schematic says. Also Try a meter on the white wire and see if it has any output.

Edited March 24, 2018 by 19richie66

[incabman 16]

You can run this engine on the bench with no wires connected to anything. Just touch the starter with 12 volts from a battery or charger and it will run if it is able. To kill it just pull the plug wire and you will have no worries about possible damage to any components. 

ezy peezy.

[clueless 3,052]

Tyson, the first thing you have to do is find out if you have a regulator. If you do then the purple/violet wire is not your kill switch. I have a M12 and a M8 with regulators. the violet wire is from the regulator to the R terminal on the ignition switch. I also have had the M8 and the M10 with the unregulated charging system, no purple/violet wire. I think the wire was blue.

[clueless 3,052]

1 minute ago, incabman said:

You can run this engine on the bench with no wires connected to anything. Just touch the starter with 12 volts from a battery or charger and it will run if it is able. To kill it just pull the plug wire and you will have no worries about possible damage to any components. 

ezy peezy.

[wallfish 17,153]

Or just cover the carb opening with your hand or choke it to kill it, no guessing for wires or getting zapped by the plug wire.

Still not a bad idea to test them while it's running so you know exactly what they are. I always thought Kohler used the white wire for kill but that diagram shows different

Edited March 24, 2018 by wallfish

[953 nut 56,613]

The M12 on my 312-8 has a violet wire from the regulator and the white is a kill wire.