I've had my Yamaha generator for about 3 years and it has decided to run badly. It is surging constantly or maybe the term (govener hunting) would better describe my problem.
We use it while camping to power my wifes c-pap machine and have had no problems until a week ago. It's much worse when running a very light load when the engine is at it's lowest speed.
I have changed the engine oil annually and kept the air filter clean and lightly oiled as per the manual. I have also cleaned the exhaust screen, but nothing has helped. A new spark plug gapped .026 also hasn't solved the problem.
Do any of you have a suggestion as to what might be causing this, Thanks Glenn
Hi Glenn,I would suggest you run it under a heavy load for 45-60 minutes. Let it cool down and check the color of the sparkplug,or post a picture of it ,this would be even better, it will tell us if we have a rich or lean condition. Have a go and keep me updated.
Speedy, the plug looks like it is brand new, the only discoloration is on the rim of the plug surrounding the electrode, then it's only showing traces of purple. I've never seen such a clean spark plug, but I've also never removed one after only an hour of use.
Like I said I feel it may be running a little lean.
This all started quiet suddenly so I'm wondering if a small peice of trash made it's way to the carberator, what do you think.
Good morning, you will have to run the Generator under load long enough to color the entire plug to get a proper idea of what is going on inside.Like I said post a picture when you have it and we can discuss it then we will have a better handle on it.
Hi Glen thanks for the pictures, this picture shows a rich condition....you mentioned that your air filter is lightly oiled. Is it oiled with 10w30 or something like that or is it air filter oil which is quite sticky.
The reason I ask is, if its motor oil the generator will suck it out of the air filter when under load. This will make it run poorly and foul a plug.