Hi all.I have a Yamaha EF2400ishc inverter/generator.Bought it new in 2010.It's been a great generator.In the last few months it's been sputtering after a few minutes of run time. It will do this whether or not there is a load. I use a 1500 watt space heater and a fan set on high for load testing.The carburetor has been rebuilt. Oil changed. New spark plug with gap checked. Gas tank drained and new gas put in.I think I've narrowed it down to the MOTOR UNIT ASSY part number 7CF-81802-19-00.My question is, what does this part do for the carburetor?Thanks in advance.

It's a servo motor that positions the throttle. It's part of the electronic governor system.

Thanks for the reply Tom.In your opinion, could this part go bad and cause the sputtering?

It's possible but I don't know what the troubleshooting procedure would be. Before you spend the bucks to replace it, try running a heavy dose of Sea Foam through it. My 1000 watt Yamaha would run rough unless partial choke was used. I ran some Sea Foam through it and that cleared it up.

Whether fuel has anything to do with or not, DO NOT use gas with ethanol. Small engines don't handle it well and it can cause breakdown of non metal components.

rrupert wrote:Whether fuel has anything to do with or not, DO NOT use gas with ethanol. Small engines don't handle it well and it can cause breakdown of non metal components.Since not using ethanol gas in my small engines I have virtually eliminated running problems.When traveling I will not go out of my way for non ethanol and only use it when easily available, using ethanol gas as needed. But the last tank for my Honda gen is always non ethanol and run it dry before storing.

Yamaha EF2400ishc inverter/generator question | Good Sam Community

brant_c
Explorer
Mar 19, 2019
Got a bottle of SeaFoam this past weekend.

I was able to run the generator/inverter for two hours without sputter.

I was also able to find a gas station 30 miles from the house that sells non-ethanol gas.

Thanks Tom.
philh
Explorer II
Mar 02, 2019
brant_c wrote:
Thank you gang.
Love this site.
I will get SeaFoam and begin using.

As for using non-ethanol gas...I have not seen any stations in my area that sells non-ethanol gas.

I only run non-ethanol gas in my generator or lawn equipment.
Tom_M1
Explorer
Mar 02, 2019
Try:
https://www.pure-gas.org
brant_c
Explorer
Mar 02, 2019
Thank you gang.
Love this site.
I will get SeaFoam and begin using.

As for using non-ethanol gas...I have not seen any stations in my area that sells non-ethanol gas.
Bobbo
Explorer II
Mar 02, 2019
Tom_M wrote:
It's possible but I don't know what the troubleshooting procedure would be. Before you spend the bucks to replace it, try running a heavy dose of Sea Foam through it. My 1000 watt Yamaha would run rough unless partial choke was used. I ran some Sea Foam through it and that cleared it up.

Tom's suggestion is top notch. I have a riding lawn mower that got to where it wouldn't start unless I used starting fluid (ether) sprayed into the carb. Even after starting, I had to keep it partially choked. Before spending money on it, I bought some Seafoam and ran the mower with double strength Seafoam in it for a season. At the end of the season, the mower was starting like a champ and running like a sewing maching. After that, I use seafoam, at recommended concentration, in everything I own that takes gasoline, except the cars.
Dave_H_M
Explorer II
Mar 02, 2019
I would go the route Tom suggested and if that does not do it, take a relook at the carb.
jjrbus
Explorer
Feb 28, 2019
rrupert wrote:
Whether fuel has anything to do with or not, DO NOT use gas with ethanol. Small engines don't handle it well and it can cause breakdown of non metal components.

Since not using ethanol gas in my small engines I have virtually eliminated running problems.

When traveling I will not go out of my way for non ethanol and only use it when easily available, using ethanol gas as needed. But the last tank for my Honda gen is always non ethanol and run it dry before storing.
rrupert
Explorer
Feb 28, 2019
Whether fuel has anything to do with or not, DO NOT use gas with ethanol. Small engines don't handle it well and it can cause breakdown of non metal components.
Tom_M1
Explorer
Feb 27, 2019
It's possible but I don't know what the troubleshooting procedure would be. Before you spend the bucks to replace it, try running a heavy dose of Sea Foam through it. My 1000 watt Yamaha would run rough unless partial choke was used. I ran some Sea Foam through it and that cleared it up.
brant_c
Explorer
Feb 27, 2019
Thanks for the reply Tom.
In your opinion, could this part go bad and cause the sputtering?