Honda gx 390 only starts when it feels like it

Voltage regulator, carbon buildup in the cylinders, the carburetor may need overhauling, engine governor may have a stretched spring, Spark plug may need replacing, Timing may be off, air filter may need changing, and lastly, your load may exceed the ability of the generator.Checking this list will uncover the loss of power

The ignition timing may be too advanced . Some times if the pull start rope is not pulled hard enough it will kick back, The ignition fires just before top dead center , if not pulled hard enough it will kick back.

you have a dingo, ugh
I would suspect a bad pump or wheel motor if the rpms are set correctly and no safety switches are causing it to die...

15 seconds it is running out of gas. check flow from the tank.

Bad coil or flywheel is very suspect probably leaning twords flywheel

check the valve adjustment

iS THE SPARK PLUG FIRING ? if not try a new one, i f it still wont fire have coil checked.

powerboss generator wont start,,fresh fuel,fire to plug,clean float bowl,,,,,,honda gtx 390 motor,,,,13 hp,,,help

Most honda engines have an oil sensor that prevents the engine from starting if the oil level is low or oil is dirty. Test coil by disconnecting oil sensor wire. With sensor disconnected coil should fire. If still no fire, check kill wire for short. If still no spark, coil may need to be replaced. enjoy