Ef 2400 Is Yamaha generator Over Revs

Very old thread but here goes., My 2400is was surging under light load but I was able to fix that with a new idle jet and thorugh carb cleaning. Now, it doesn't respond to various loads and will not rev up, ie., stays at idle and quits. Manually opening the throttle works fine. I took out the solenoid and cleaned the spindle but didn't help. When it was out, turning it had some resistance (felt like a rehostat, a bit rough and definitely not spinning freely) . Dunno how it should feel but, for example, with the engine not running if I move the throttle (controlled by the solenoid) it will "stick" in that position and not return to the idle position by the return spring. Would like to know if that's normal or not! With the engine running, it will return to the idle position and I use a clothespin to keep the revs up even under no load. At least that way it stays running and supplies adequate power.
Ideas?

You idle jets may be adjusted correctly but other jets may need cleaning out. Also check float height. They may be too low and cause hesitation under load

There is something wrong with the auto load sensing switch which is part of the generator. That is the sensor that detects when current load from the generator drops as in when you strike an arc or turn on a power tool and cranks the throttle to full power. It is obviously working on manual because the manual switch is cranking the revs up so the solenoid that operates the throttle is ok. My advice is to take it to a service centre that deals in welder/generator sets as you are playing with dangerous voltages and may possibly damage the machine by tinkering with it or fry yourself (nasty)

If may be a partly blocked main jet ( Check by slowly closing the choke), if it the hunting clears out as you slowly close it it prob blocked main or pilot jet...
If the unit hunts (flutter)at 1/4 through 3/4 load, the governor damper spring on the throttle shaft under the stepper motor needs one more turn.. only after you've checker the carby..Only one turn or you will damage the stepper motor....one a few of these....

Idle speed screw may need adjusting slightly to increase idle speed. Also Main jet and Idle mixture Screws may also be out of adjustment

souinds like a worn clutch to me, or badly out of adjustment

Hi, I just pulled out my Coleman Generator (1000) and it actually started then died. Has been sitting for about 10 months. I ran it out of fuel before putting away. Anyways, it starts for a minute than dies. If I press fuel primer it keeps running but than it dies. So, I took the cover off, the one towards exhaust side and was able to see carburetor. There are two screws with springs on them. I guess these screws control fuel and air for carburetor(you can clearly see they are on carb). As stated above there are not many adjustments. There is no choke for the model I have; just an on and off switch and fuel prime button. The instructions say fuel it up (with the right oil/petrol mix of coarse), switch it to "on", prime it, pull starter cord and then that's it......"not happening". Okay, so I took my little flat head screwdriver and backed out each screw while counting how many times I turned, until I was able to remove completely(PLEASE remove one at a time and take note which one went where AND how many times you backed out). Take a can of carb cleaner with the straw and shoot through the holes where the screws came out of. I shot carb cleaner a couple pumps in each hole. Examine each of screws removed as these have pointed ends(replace if damaged). Put screws back; again make sure you count how many turns. This worked for me. Idles perfect. Thanks!

ur having fuel supply or poor electrical supply problem thats why the engine cuts off underload/ check spark plugs or airflow meter condition as well....

I'm not quite sure if your issue may relate to most inverter and auto-load sensing generators or some gas-powered equipment.
Most power cutters/grinders such as Stihl or Husqvarna, specially the higher cc models do sound crappy without load, you'd think there's something wrong with it from day 1. This is normal. Well, some of these machines lack the load sensing capability thus does not adjust throttle variably according to load.
Modern generators, specially the inverter ones along the 1000 to 3000 watt range where the Yamaha 2400 falls into category, have a switch where you can choose to let the unit sense and adjust throttle according to load. If this is off, the unit might sound like its not running smoothly on idle. Depending on you, this can be alarming or not. On a Honda EU2000is, for example, it is noticeable when the auto-load sensing button is off but not be like its choking or sputtering.
Anyhow if it is idling roughly, I can only come up with 2 possible causes, if I may suggest:
1.) the cable that gradually pulls the throttle (to open wide or close) on the carburetor - normally called governor cable (although it has different configurations on different engine types) needs to be adjusted/tightened. Or replaced, if worn out. Before new cable, put lithium grease on cable - it helps a lot.
2.) throttle adjustment might be necessary. At most Yamaha servicing dealers, it is included when you have a carburetor tune-up. They will check the diaphragm for blockage or holes, gaskets for leaks and filters, well, the entire integrity of your carburetor. This resolves most rough idling issues.
I know it would probably save you at least $65.00 if you have to check this yourself and buy the spare parts. However, going to a servicing dealer may be the best solution but always be sure the repairs are warratied. Hope this helps.