Coleman Pro gen generator 5250 with a Surbaru engine. Engine starts and wants to run wide open throttle. It is not under load.

SOURCE: COLEMAN POWERMATE 6875 11 HP GENERATOR

Sounds like the push button circuit breakers have tripped, try pushing them back in to re set.

SOURCE: What type of oil for a Coleman 5000 Generator?

You need a quart of regular old SAE 5W30 motor oil with detergent.
The engines on these generators are more or less the same as a lawn mower.
Don't forget to service/change the air cleaner when you change the oil, that should keep your generator producing full power.

Regards,
Carl

SOURCE: coleman 5000 generator will not idle up under load

Hi

You have to find the governor linkage.There is a spring adjusting by a screw to increese speed to get more power.Try to locate it.

best regards savumihai71

SOURCE: I HAVE A GENERATOR THE MOTOR SURGES ONLY WHEN LOAD ARM IS CONECTE

replace the pink plastic jet and two O-rings (center of carb) and clean out the shaft they are in with Q-tip and solvent, blow out with compressed air prior to assembly, make sure a old O-ring is not down in the hole as this is a very common mistake made by many who make repairs, one O-ring will remain in the shaft after you pull the jet out. 4 out of 6 gens that surge have this problem especially if you hear a small amount of backfiring . the bottom jet must be very clean as well if it is the newer model without the thumb screw.

SOURCE: COLEMAN powermate 5000 generator w/a Subaru engine

Check the vent in the fuel cap to make sure its free to breath. It could be creating a vaccume in there and starveing for fuel. Maybe run it with the gas cap off and see if the problem gos away.