I have a Champion generator 6000 starting watts modle number 41115 starts and runs for a few minutes then shuts down , has fresh gas and new spark plug.

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: auto idle on a reddy rgh11000 ie will not idle down

This sounds like the idle control solenoid has become misadjusted. To check that this is the case, locate the throttle lever and follow it back towards the governor arm until you find the solenoid. Start the generator and switch on the idle control while watching the governor arm where it passes near the solenoid, if the arm snaps back and forth you probably have a bad adjustment. To readjust the solenoid loosen the jam nut on the core of the solenoid just enough that you can turn the core by the square bit on the end. Adjust the core 1/4 turn or so at a time until the governor arm stays in position when the idle control is on, then turn idle control off and make sure that the governor arm goes back to the full throttle position. You may have to fiddle with the adjustment a little until you find the right spot. Tighten the jam nut back down and you're good to go.

Carl

SOURCE: My troy-Bilt 5550 watt generator will not start

First drain the fuel bowl. Any old fuel in there will keep it from starting. Fuel stabilizer is not what it's it cracked up to be. I've worked for 6yrs at a rental yard and had no luck with any fuel stabilizer, the fuel still went bad. If after you drain the fuel bowl it still will not start, you will need to clean the carb. Remove the carb and spray carb cleaner through all the accessible passages. If this does not do it, you will need to replace the carb. For long term storage I highly recommend draining all the fuel and filling just the carb with fuel stabilizer to keep gaskets moist. Then drain the carb when you take it out of storage.

SOURCE: VALSI 5,500 WATT GENERATOR WILL NOT START

All generators need to be run once a month. All things from the tank to the and including the carb will get gummed up with dried out fuel. I have a whole house generator and a 5500 watt gen set on my motor home. I keep fresh fuel in the stand alone house generator in California in case of a bad earthquake. I drain the gas after every run and keep all vehicles full of fuel just in case. Run gen sets at least once a month or pay pay pay!!

SOURCE: My 5250 watt Power Back generator will not start,

Have you check the engine oil level?If it is down on oil you won't get spark because of the oil level switch shutting the ignition down to protect it's self.