I have Yamaha EF3000ISEB my ignition start with with key just clicks but no turn Over

Is it not old go for warranty , almost the starter motor itself ,start by trigger
Yamaha ef3000i se generator service repair manual download

Is it a single click as you turn the ignition on or a series of clicks as you press the starter button? A series of clicks points to the starter solenoid being faulty. Follow the positive cable from the battery and you should find the relay (suzuki's are cylindrical in shape I believe) and see if the clicking is here. If so. with the ignition on short across the 2 bolted cable connections momentarily with a screwdriver and see if it turns over or starts. Careful, don't allow the short to touch the frame. Hope this helps.

Sounds like gummed carb, you may have to pull apart and clean the jets.

Could be a bad ignition switch. if the system isn't getting signal it won't start.

Yes thats true
there is high altitude re jetting in the carburator your carb has to be re jetted for the normal operation of the generator at high altitudes by the authorised personel but when you will bring it back again at the orignal altitude it will get heated quickly and may not function properly so you will have to bring the carb settings to its orignal position so be careful

check clutch lockout switch and side stand switch, check fuses, do you hear a the relay click