Yamaha EF3000iSE generator surging

[Sureshot]

My generator surges when in the econo mode. Once under load it idles up as it should to meet the demand put on it. It used to work good. Since it started acting up I have put a few tanks of premium loaded with Seafoam and other "cleaners" through it hoping it was a simple fix. I let them sit in it at times and then ran it again. I am leaning to a fuel issue from sitting over a winter but I am also unfamiliar with how the load sensor etc work.

Anyone with experience or good ideas?

 

[PrecisionTools]

Have a bit of a look through the service manual here...

https://hotfile.com/dl/186001279/c381561/EF3000i_Service_Manual_7wle0.pdf.html

There is a section in the trouble shooting guide that might help you out, otherwise check all the service items first and see if its all OK - air filter, muffler, valve clearances etc.

Let us know how you get on.

 

[Burtonrider10022]

Define "surges"... The RPMs of the gas motor spike or the voltage/amperage spikes?

Either way, it's a little late now but you really really should run you generator for 10-15 minutes every other week or so, and put a load on it as well. This not only keeps the gas engine in better shape but it also keeps the windings in the gen-head unit in better shape.

 

[Blkhawk870]

When an engine surges it typically means in is running in a lean condition. If the engine has sat for a long time it is very likely that some of the jets in the carburetor are gummed up with old gas.

Since it runs well under load, that indicates the idle jet is partially blocked. I've found that Seafoam and other cleaners do not work that well. You will most likely have to remove and clean the carburetor.

 

[mobiledynamics]

Pretty much BlkHawk summed it up. Additives won't help you. Pull the carb and get the wire ready for a manual cleaning...

 

[theoldwizard1]

Pretty much BlkHawk summed it up. Additives won't help you. Pull the carb and get the wire ready for a manual cleaning...

I disagree ! If the engines starts and runs, even surging, you frequently can get it to "clean itself".

Mix up about 1 gallon of gasoline and Seafoam at about 4 times the normal ratio. Drain existing gasoline and fill with the new gasoline.

Start and run it on a "heavy" load. A couple of cheap electric heaters (Walmart under $20) are a good load. Turn the load off for about 1-3 minutes every 10-15 minutes. Run the whole tank.

If this doesn't clear it, THEN you need to pull the carb. Disassemble and soak overnight in a bucket of ChemDip. (Available at most auto parts store for about $20. Keep it sealed and it will last a lifetime.) You will probably need some new gaskets, but not the needle and seat.

 

[theoldwizard1]

... you really should run you generator for 10-15 minutes every other week or so, and put a load on it as well.

I only run mine about every 2-3 months, but loaded is important.

I do run the carb bowl dry.

 

[Charles (in GA)]

Our Community well has a Genrac/Dayton 10K watt for running the pump in an emergency. It has a load sensor and idle mode. When it senses any draw, an electric motor brings the throttle to full and the governor takes over to maintain RPM. In idle mode, it is on the idle stop screw. I recently got ours and went over it, changing the oil and filter and draining the fuel tank of old fuel and replacing the fuel hoses. It would not idle smooth at all in idle mode and did semi OK in the full power mode.

I ended up removing the cover to the carb and pulling the float and it had a lot of grit in the float bowl. Carefully blew out the passages in the body and cover, making sure no loose ball bearings, needles, etc got lost, and reassembled it and held down the float shaft retainer and allowed it to fill. Floats shut off when flush with the top of the body, so I reinstalled the carb top and it ran fine after that.....

Other problem I have run into in the past. There is an oil pressure switch that kills the engine if there is no oil pressure. Usually there is a time delay of about 30 secs so the engine can start, then the pressure switch is put into the circuit.

If you have a bad or near bad switch, it may be make/break/make at idle due to low oil pressure and causing the ignition to cut in and out. On ours, the switch was totally bad, and the motor would start and run 30 secs and die. Finally figured out the switch and time delay, and replaced the switch and fixed it.

Charles

 

[SpeedCoach]

Whenever I hear a description of surging, I immediately go to the carb being dirty. Especially the "low" side of a motor. I've seen precisely what you describe on the eco mode side of my Honda generators. Running them with a load will usually clean them out....especially if you have a stabilizer or cleaner (sea foam) in the fuel. Having had this issue, and having taken my carbs apart to clean them, I've since not let my gens have any fuel go through the, that isn't treated. And since then I've had no trouble (4+ years)

 

[Sureshot]

I have run multiple tanks with a heavy seafoam content with it under load to varying degrees. Left it sit for hours and days with strong solutions in it. I just was looking for other potential issues before tearing it apart.

I do generally try to start it and run it often but sometimes life gets too hectic and it sits. I think it got left in the camper over the winter then not used until fall so it likely got a little something in it.

The surging is the engine. It does it under no load. I put a 750/1500 watt heater on it and it bumps up perfect to match the load. Would not be so bad but when we use it to run the AC on the camper it is terribly annoying when the compressor kicks out. I ran it in the box of the pickup all summer when driving to run the AC and hoping to "self clean" but no luck. I will have to crack it open.

 

[Burtonrider10022]

I only run mine about every 2-3 months, but loaded is important.

I do run the carb bowl dry.

I didn't say I run mine that often, I said it SHOULD be run that often! I am a bit more frequent than you, I average about once a month. I like to let my pancake compressor fill up while running my heat gun. That really stretches the little Briggs & Strattons legs. She loves it that little ****.

I have run multiple tanks with a heavy seafoam content with it under load to varying degrees. Left it sit for hours and days with strong solutions in it. I just was looking for other potential issues before tearing it apart.

I do generally try to start it and run it often but sometimes life gets too hectic and it sits. I think it got left in the camper over the winter then not used until fall so it likely got a little something in it.

The surging is the engine. It does it under no load. I put a 750/1500 watt heater on it and it bumps up perfect to match the load. Would not be so bad but when we use it to run the AC on the camper it is terribly annoying when the compressor kicks out. I ran it in the box of the pickup all summer when driving to run the AC and hoping to "self clean" but no luck. I will have to crack it open.

You can always try a stronger, carb specific additive and give it one last chance, but otherwise, yes, it sounds like a good carb cleaning is in order. Going forward try to use SeaFoam preventatively and drain the carbs when the gen-set is being stored.

 

[mobiledynamics]

Aside from the wonderful smoke show, does anyone really see a difference using Seafoam ?

How about taking something carboned up, soak it in Seafoam and then try to scratch it off by hand. I'd be curious to head the results....

 

[theoldwizard1]

Aside from the wonderful smoke show, does anyone really see a difference using Seafoam ?

You only get the "smoke show" if you do the de-carboning treatment. As a general carb/injector cleaner (mixed into fuel) it works quite well.

How about taking something carboned up, soak it in Seafoam and then try to scratch it off by hand. I'd be curious to head the results....

The main "active" ingredient in Seafoam is naptha. Naptha is an excellent carbon solvent. In theory, if you placed a heavily carboned piston in Seafoam/naptha most of the carbon should dissolve.

 

[Sureshot]

So just a follow up on this in case anyone finds it in a search. The inside of the carb was spotless.
The idle jet is accessible from the outside on top if you remove the electric throttle control. It was plugged solid. Spray carb cleaner etc wouldn't clear it but 5 minutes in "real" carb cleaner had it cleared.
Back to running like a top.

You can download the service manual in PDF on the net and the parts breakdown is on 3-45. Item 18, pilot jet.

"Mikuni Pilot Jet B-Type Butterfly Carb N101.043/37.5" is the part if you want to get one in advance. I found them for a couple buck on flea bay so I have spares in the camper. I ordered 3 spares. Two to drop in the mud and one to use.

 

[laser3kw]

"never mind"
I didn't read what I thought I read - it's early - need more coffee

 

[OccupantRJ]

So just a follow up on this in case anyone finds it in a search. The inside of the carb was spotless.
The idle jet is accessible from the outside on top if you remove the electric throttle control. It was plugged solid. Spray carb cleaner etc wouldn't clear it but 5 minutes in "real" carb cleaner had it cleared.
Back to running like a top.

You can download the service manual in PDF on the net and the parts breakdown is on 3-45. Item 18, pilot jet.

"Mikuni Pilot Jet B-Type Butterfly Carb N101.043/37.5" is the part if you want to get one in advance. I found them for a couple buck on flea bay so I have spares in the camper. I ordered 3 spares. Two to drop in the mud and one to use.

Thank you for coming back to the thread. All too often, people will get the help they need and never respond with the results obtained. Reply-backs like this are valuable to others.

 

[crucible]

So just a follow up on this in case anyone finds it in a search. The inside of the carb was spotless.
The idle jet is accessible from the outside on top if you remove the electric throttle control. It was plugged solid. Spray carb cleaner etc wouldn't clear it but 5 minutes in "real" carb cleaner had it cleared.
Back to running like a top.

You can download the service manual in PDF on the net and the parts breakdown is on 3-45. Item 18, pilot jet.

"Mikuni Pilot Jet B-Type Butterfly Carb N101.043/37.5" is the part if you want to get one in advance. I found them for a couple buck on flea bay so I have spares in the camper. I ordered 3 spares. Two to drop in the mud and one to use.

Yep-thanks for coming back with this-I have the smaller cousin of your 3000 (an EF24000isHC) and this is handy info!

C-

 

[NH-Hitchhiker]

This sounds like the solution to the idle surging problem that I am having. Do I have to remove the carburetor to gain access to the idle (pilot) jet, or just the electronic idle control module, and if it's only the module is it just the one screw on the bracket? Thanks for your help, Ron

 

[Sureshot]

This sounds like the solution to the idle surging problem that I am having. Do I have to remove the carburetor to gain access to the idle (pilot) jet, or just the electronic idle control module, and if it's only the module is it just the one screw on the bracket? Thanks for your help, Ron

You can download the service manual in PDF on the net and the parts breakdown is on 3-45. Item 18, pilot jet.

You don't need to remove the carb, just the control module.

Link to Service Manual.
https://www.dropbox.com/s/jxgkfvxfy530dmh/Yamaha EF3000i Service Manual 7wle0.pdf

 

[theoldwizard1]

Spray carb cleaner will not always clean out a jet. Pull a single wire from a wire brush, bend it straight and use that to probe into the jet/passage. Then spray.

 

[jbar]

I Came Across This Thread While Searching For A Solution To My 3000 Iseb Surging While In Economode. My Problem Was Solved By Using Theoldwizard1's Advice.

InThe Empty Fuel Cell I Put In A 1 Gallon Mixture Of Gas/ 4 Oz. Seafoam. I Let It Run For 15 Min Under Full Load, Then Turned It Off For 10 MiN. I Repeated This Procedure 1 More Time And The Generator Was Back To Running As It Should.

I Appreciate Everyone Sharing Their Experience And Knowledge!

 

[Glammers37]

Thanks a ton for the info and the follow up. This site is such a good resource! My Yamaha is doing exactly the same thing. I am going to check into this. Already downloaded the manual. Thanks again!

 

[Palmettosunshine]

I disagree ! If the engines starts and runs, even surging, you frequently can get it to "clean itself".

Mix up about 1 gallon of gasoline and Seafoam at about 4 times the normal ratio. Drain existing gasoline and fill with the new gasoline.

Start and run it on a "heavy" load. A couple of cheap electric heaters (Walmart under $20) are a good load. Turn the load off for about 1-3 minutes every 10-15 minutes. Run the whole tank.

If this doesn't clear it, THEN you need to pull the carb. Disassemble and soak overnight in a bucket of ChemDip. (Available at most auto parts store for about $20. Keep it sealed and it will last a lifetime.) You will probably need some new gaskets, but not the needle and seat.

Holy Zombie post Batman! I know I'm resurrecting an ancient thread but I wanted to thank Oldwizard1 for his response. It saved me having to tear down the carbs on a couple of my generators that I left a little too long with gas in them.

We're getting ready for Hurricane Matthew here in Myrtle Beach and when I fired up the generators yesterday they ran like ****. Searched all over the web for help and stumbled across this old thread. After running Seafoam and fresh gas through them under load as suggested by Oldwizard1 they are smoothing out nicely.

Thanks for posting this as it worked for me. I may just hang around and see what else I can learn here.