I have a devilbiss generator mdel #gb5005 runs great but no power output any ideas

http://ezinearticles.com/?No-Generator-Output?-Flashing-The-Field-To-Fix-Or-Troubleshoot&id=6808803

With no load on the generator, take a voltage reading at the output plug of the generator, if there is no voltage, check to make sure that no breakers are tripped or fuses blown.

check brushes maybe stuck

1. Make sure that the generator limit is not being exceeded.
2. Try checking and raising the rpm. If the engine can not sustain the load from the generator, it can/will trip the breaker.
3. If the carb is dirty or the engine runs poorly it can trip the breaker. Tune up the engine, clean the carb, make carb adjustments to correct substandard running conditions.

they have reset buttons usuall black push to reset

Is there voltage on generator terminals. If not you must recharge the field or check the Voltage Regulator output

There are basically 2 possibilities that can cause this.

1) Enigne RPMs are too low. but, since you already played with the throttle, this probably isn't the case. RPMs should be about 3600 though.

2) The voltage regulator / capacitor has high ESR (resistance) or is bad altogether. Replace.

i'm specialized in generators...but your problem seems familure...
try getting an L14-20 female connector ...i wish i had more details but this is all i can advice.

not to familiar with the generators however , I do know that the old style receptacle for 240 volts was three prong. Then OSHA got a hold of it and added a second ground to make it 4 prong, Thats why some houses use a 3 prong dryer cord and some use a 4 prong. hope this helps. and if it has 2 240v outputs BONUS they dont make em like they used to.