I have a generator Kohler Model 30 RES IT CRANKS AND RUN FOR FEW SECONDS AND SHUTS DOWN

SOURCE: kohler 12kw generator starts but shuts down after 3sec

Your gas pressure is too low and you may not have a large enough supply pipe. You need at least 10 inches of water column with the engine running to operate an LP vapor fueled engine. Because the engine is starving for fuel, its governor opens the throttle to WOT (so it goes to high revs) but there isn't any fuel to make horsepower with so the output voltage falls and the undervoltage alarm trips.

Carl

SOURCE: kohler lp shuts down

What you need to know is there enough fuel going to the regulator. It should be 7 to 11 inches Water Column. If not your problem may be not enough fuel. That includes when the heater in your house kicks on and what ever gas appliance you may have. Once you verify that you need to figure out if you have the proper pressure coming out of the regular on the inside of the generator. Next I would look at compression of the cylinders. It may need new piston rings.

SOURCE: I have a new Kohler 12kw res generator on propane - backfiring

did you put the propane orifis in and unplug the spark wire

SOURCE: I have a Kohler 12RES, 12.5kw genset. Less than a

Replace mag pick up. Cranking voltage on the MPU should be at least 2 volts AC. Normally MPU goes out.

SOURCE: I have a Kohler 12RESM1 propane generator with oc/uu code

U need to make sure that the relay driving ur auto start stay closed all thru the crank cycle.