Kohler generator help

[Mrbigler]

I purchased a 1987 3207 that has a generator issue. It is a Kohler 7.5R27 (106276-A), serial #177842.
The generator starts and runs for 30 seconds then shuts down. If I disconnect the ground lead from the magneto the engine will run 1 minute then shut down.
I am a pretty good mechanic but don’t know anything about troubleshooting generators.

I would truly appreciate help with troubleshooting, or if anyone has a service/troubleshooting manual, or if anyone knows a good Kohler repair person in the Sacramento area.

Thanks in advance:
Mike

[RobGunn]

I have a similar issue with my Kohler generator. Iv been told that the control board has a relay that has to sense the need for outgoing power or the unit will shut down. Also there is a oil pressure sensor that will shut the generator down if the pressure is to low. Your issue may be one of these? You wont get ANY support from Kohler, iv tried and tried... Your best bet is to find someone local that knows the unit. Maybe a local marina?

[ColRon]

Mrbigler, let me first welcome you aboard. It could be a misadjusted or faulty speed sensor, oil pressure sensor, or bad temp sensor. You will also need to determine if yours has relay circuitry or is solid state. Solid state has 3 switches and 3 fuses on the generator control panel and the relay circuitry on has one switch and two fuses.

There are about 7 difference things that can cause it to shutdown within the first minute. With the three noted above as the first things to check.

Pm me your email address and I can forward an electronic copy of the service manual for the 7.5R genset. This also goes for anyone else who wants a copy of the Service Manual for the 7.5R. I also have an owners and parts manuals too.

[Mrbigler]

An update on my Kohler problem. Thanks to Ron for sending me a digital manual that had a troubleshooting guide. My 7.5R27 is a Relay version (not solid state). There is 1 small board with 3 relays, a multi pin connector and a large capacitor. When I unplugged the connector so I could remove the board for closer examination, I noticed one of the board side pins was broke off in the plug. Then pin happened to be the B+ connection. Fortunately I spent 14 years in the 80’s and 90’s as a component level board technician. I took their board home and manufactured a new pin, soldered it in and solved my issue. Generator now runs great and produces power.
Thanks to those who tried to help, I really appreciate it. Mike

[ColRon]

glad to hear you got it repaired!

[RGrew176]

Just love a happy ending.

[Keith S]

I find your issue interesting. Removing the grounding lead from the magneto removes the capability of the controller to shut down the engine. Since that gen has a mechanical fuel pump, in theory it should just keep running. It is one of the ways to troubleshoot that model, unless it has an electric fuel solenoid or someone has added an electric fuel pump. The boards and relays should have no impact on it running.