Yamaha EF2400is

Does anyone have any experience with this generator? Mine has about 8 hours on it and when started will only run for a few seconds then smoothly shut off. It will not restart unless it sits for several minutes then the same thing repeats.

The spark plug is clean and dry when I pull it out to check. Spark is present. Though I don't know if it is sparking immediately after a shutdown.

I am suspecting the low oil shutoff switch though the oil level is fine and the low oil light does not come on when it dies and stops which gives me doubts. This switch does not look very accessible to try and bypass for troubleshooting.

Iunintentionalystored it a few months with unstabilized gas in the carb. I could smell the stale stuff when I was choking itup on the 1st start attempts. I drained the float bowl twice to make sure fresh was getting to it. These things auto throttle which I am unfamiliar with and don't know if that could be a factor.

Re: Yamaha EF2400is

Jeff, it definitely sounds like fuel starvation.

You might try removing the fuel line to make sure there isn't an obstruction to the flow from the tank. If you're refilling the bowl, I kind of doubt it. It still might have a partial obstruction that doesn't allow enough flow for running.

I once solved a new lawnmower fuel problem by removing a plastic inventory label from inside the fuel tank! It would run for awhile then completely shut down. The label was getting sucked over the fuel outlet hole kind of at random!


Senior Member
Re: Yamaha EF2400is

If you stored it with fuel in it that if more than likely the problem, the gas has turned bad. Try adding a little bit of stp fuel enrichment or maybe even a little alcohol. When I did that with my honda nothing worked and we had to get the carb rebuilt.
Re: Yamaha EF2400is

Good advice and I'm agreeing.
I'm gonna clean that carb out this weekend and report back. It's long out of warranty, haven't used it much. Yamahas are just too dependable for it to be electromechanical in nature. It has to be something that I did to it. Debris or water in the jets maybe or gummed up and sticking float needle and seat . Hope I don't tear a gasket and need a kit but if I did I don't suspect they cost much.
I haven't even given it it's 1st oil change yet but about to.
I'll never leave it sitting with gas in the bowl again. :sleepy: :sleepy:
RE: Yamaha EF2400is

It justoccurredto me that since I can get lots of gas out of the float bowl drain that the needle and seat and bowl vent should be OK. Fuel is entering the bowl but not completing it's journey thru the circuitry to the discharge nozzles. So maybe water obstruction or dirt as wasadvisedby Tex. I'm leaning toward water since there is a nice refill screen under the gas cap.


Senior Member
Re: Yamaha EF2400is

hi Jeff post back what you find , btw PM me you location in GA . as you can see I am in Ga.

big bilko

Senior Member
RE: Yamaha EF2400is

Just a thought from someone who is not very into mechanics of motors. My coachman Mirada won't allow the generator to run unless the main fuel tank is over quarter full. Hope your problem is that simple. Regards BIG BILKO. :question: :question: :question: :) :) :)
RE: Yamaha EF2400is

Probably a little late for this info now, but I am a new member and was reading through the post.

I also have this generator, and have had the same problem, but have discovered the cause.

If you will take the back cover off and look, it has a vapor recovery canister, simuliar to an automobile. This is attached to the top of the gas tank, and also in line to the carberator (black plasitic, clinder shaped tubehose attached to it, an opening on one end). If you fill the generator to the very top, gas will flow down into the vapor canister. Eventually it has so much fuel, that when the generator runs, its sucking fuel out of the canister, instead of fumes, and floods out the generator. So you know, I think it sloshes around during transportation and gets in there also....

Regardless, I have found if you are having this problem, disconect the vapor hose and remove the canister (it has a little rubber retaining strap), fuel will run out of it when you tilt the canister. It lays flat on the base of the generator, and has a hole in one end. I then gently blow through the fitting where the vapor hose connects to get the remaining fuel out. Note, make sure the open end is pointed in a fuel safe direction.

As I continue to over fill my generator, I have to accomplish this every month or two. But once you put it back together, it runs like a champ again. I have considered blocking the recovery tube off, but haven't done so yet. I am pretty sure that its installed to meet "Cailifornia" small engine emission requirements. Its a great generator otherwise. Hope I am not to late to help you other people who have had the same problem. Terry