• If you like antique engines, vintage tractors or old iron machinery, register and join us. When you register on Smokstak, please give complete answers and fill in the blanks. - IF YOU ARE ON WIRELESS OR SATELLITE, ENTER YOUR CITY AND STATE! NO ZIPCODES! All registrations are manually approved.

Kohler w/ VG4D1 will start but not run

Grizzly Hill

Registered
I have a low hour Kohler Jenny (Propane- but was NG) - 15RMY62 w/ Wisc, VG4D1 Zenith 87 carb - starts fine- but will not keep running- Unless I toggle the start switch- Fuel is good- but It seems to me that it is not getting electrical power to magneto unless the start switch is activated- there is no "run" switch or ignition switch and I cannot find where the Magneto gets its power from- so I can make sure it it getting power- HELP IF YOU CAN- Thanks! Ray
 
Last edited:

I like oldstuff

Registered
Last Subscription Date
11/09/2015
If it's a magneto they are self powered by internal magnets. The wire connected to the side of the magneto is the stop wire. To stop the spark and shut the unit off this wire is grounded through a switch. That's all there is.

Your unit may have a low oil pressure cut out switch that also can shut off the engine. (This also grounds out the magneto.) Note that these engines put out very low oil pressure. Maybe 10-12 psi cold and 5-7 psi when warmed up.

See if there's a pressure switch on the oil line plumbing that runs up to the governor. It'll be down by the oil filter/dipstick. To verify pressure, you can take the switch off and put a pressure gauge in place. Take the grounding wire off the magneto and fire it up. If you have oil pressure and it continues to run you have a bad low oil pressure cut off switch.

If it still quits with the magneto stop wire disconnected you have a fuel delivery problem. *Perhaps the switch that you wiggle may be turning off the propane solenoid valve which will kill the engine.

Pic is of mine with the magneto. You can see the low oil pressure switch I installed.
 

Attachments

Jack Hottel

Subscriber
Last Subscription Date
01/02/2020
I don't know about your unit, but the 15RMY series won't stay running if AC is not produced.
Relay 1CR controls that. Unplug it and if engine continues to run check for AC output. Wiring Diagram attached.
Jack Hottel
 

Attachments

Last edited:

I like oldstuff

Registered
Last Subscription Date
11/09/2015
Yeah without AC or low AC the overcrank switch will actuate and stop cranking. Seems to take about 15 seconds on mine.
 

Andrew Mackey

Moderator
Last Subscription Date
05/14/2017
The others have pretty well covered it. Low voltage or a sensor. If the engine is distributer operated you might also have a fault in the ignition resister. When the engine quits, see if the coil is getting voltage. The resister is bypassed when the starter is engaged, but once the starter kicks out, the resister takes over . If the resister goes bad, the engine will quit as soon as the starter stops cranking the engine.
 

Grizzly Hill

Registered
Seems like the OVERCRANK WATER TEMP OIL PRESS RESET-
Switch is broken but I cannot find the switch listed anywhere in the Kohler parts listing- it is a strange switch with the numbers "APGN1 / 8347-1 /1REC2
no other identifiers on the switch-
 

q930

Registered
[Your unit may have a low oil pressure cut out switch that also can shut off the engine. (This also grounds out the magneto.) Note that these engines put out very low oil pressure. Maybe 10-12 psi cold and 5-7 psi when warmed up.]

I like oldstuff: If the low pressure cut-out switch grounds out the magneto, how do you get it started? Obviously there's no pressure when the engine is not running, so you'd should never be able to get a spark until you get pressure. Or am I missing something?
Thanks. I enjoy your comments.
Terry Q.
NW Wis.
 

I like oldstuff

Registered
Last Subscription Date
11/09/2015
930:
When you crank the engine yes, the low pressure switch is killing the spark. It takes about 8-10?? seconds of cranking then it lights off when the spark is enabled. When it's cold like 20 degrees or less it takes longer before it fires up.
Bear in mind as it's a splashy squirty oiling system, the switch enables spark at I think 2-3 psi.

On mine I added a bypass switch that disables the LOP switch. Then it fires quickly. Once it's running that switch is flipped which enables the low pressure switch to kill it.

Mine is nat gas and I plug in the fuel hose when I run it. It takes 8-10 seconds of cranking to get the hose purged and the gas to the carb.
Once it's been running and on a restart it's like 2-3 seconds of cranking before it kicks off.
 

Attachments

Last edited:
Top