Blackmax8450 generator pm0496750 won't start help me

give tune up and flush fuel system and possible may have to rebuild or replace the carb

If it has sat, it may have lost it's rotor residual magnetism.
Disconnect the rotor field wires at the AVR or on the exciter/brushes. Note they are polaroty sensitive. Connect a 12V battery to F+ and F- (note polarity) and momentarilly power from the battery for a few seconds. DO NOT forget to disconnect the rotor/exciter field wires first or the voltage regulator will be damaged.

If it hasn't sat check voltage regulator, rotor resistance, and stator resistance, and for shorts to ground.

You have excessive arching on the rotor slip rings by the sound of it, if you clean them and it works well then 3 hours later same problem? What is the conditon of the brushes? Also I trust youa r enot cleaning polishing them with sanpaper etc, they have a very fine finish and should be polished with a super fine grit paper or stone, pref while turning the engine. Any scratches won't work

I doubt its anything to do with brushes unless power system has shutdown incorporated, could ignition coil breaking down when it gets really hot or similar check the oil level cut out switch

I would let it cool completely and see if it starts again. There are no specific timers that say after detecting a low oil shutdown don't start for X amount of time. It is more than likely a choke setting as it is hot, and you may now have flooded it.

did you try cleaning the conductor that goes to the spark plug if not try to clean it with a real fine sand paper it should do the job.

Hi,
I have a EM5000SX. My problem is my generator will not start unless I turn the fuel selector to off. Then crank it until it does start, turn the fuel back on. Run's normal . I run this generator for my cabin every weekend.

Could be vapor locked. Prime the line and try again.

Main jet is clogged

change spark plug and add small amount of starting fluid to breather pull with all settings in proper place if it is going to start it will or you have other problems