Hi I got a 3000 yamaha generator with no output what ya think problem could be

Allmost all generators have little circuit breakers that when tripped will shut down the power output...

Is it not old go for warranty , almost the starter motor itself ,start by trigger
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Hal, you may be able to adjust some what by changing engine RPM(throttle *****) and playing with the governor if need be with no load and with load.

Portable generator voltage regulator

Onan generator adjustment run speed voltage

https://mtspowerproducts.com/admin/data_sheet/SS321Manual%20II.pdf

Possible dirty contact or defective.

sounds like the carberator needs cleaning and the linkage that makes it open up under load. it works off the flywheel. a lot of generator problems are gas related. water, trash and varnish build up in the carb.

13.5 amps is what you alternator puts out 625 watts 28ah.

Your generator/alternator has an output of 37 Watts @ 8,000 rpm ( 12v x 3.1 amps = 37.2 watts) all the best....BLASTUS

hmm.... try running it for a while with something plugged in that won't mind the voltage drop... like a light bulb..

check that your float has not perforated

Does your generator is single phase generator set or three phase four wire generator? Why your generator set is 110V at full load, it should be 220V or 240V to generator electricity. If it is used for industrial equipment, it should be 380V, 400V, 440V, etc.
Generator technical support: https://www.dieselgeneratortech.com/support/