Generator surging, Need advice

[smokey]

I have a Porter-Cable 5500 watt generator that is driving me nuts and I could really use some help figuring out.

 I bought it in 2009, (I think it is just a re-branded Briggs & Stratton) 10 HP B&S engine. I use Pri-G in my stored fuel and rotate it regularly. Oil is 10-30 synthetic.  I start it every month and run it with a load. It probably has about 200 hours on it.

 This month I started it just like always, Started on the first pull. But then it started surging, engine would speed up and slow down constantly with a pop or backfire thrown in for good measure.

 Drained tank and refilled with fresh non-ethanol fuel.

 Tried a new spark plug, No help

 Air filter is clean.

 I thought maybe the carb was dirty or clogged so I pulled it off for a cleaning. It wasn't bad but I cleaned it anyway and tried it again. Same problem still going on so I decided to try a new spare carb I have (OEM Briggs carb) and if anything the problem is worse. 


 So.... What the heck am I missing here? Bear in mind that I am NOT a mechanic, So if it's something dead simple just assume I don't know about it and mention it anyway. Any help is appreciated.

[Deleted]

I don't have the same type generator, and since you've pulled your carb you probably already covered this aspect, but mine was doing that. It turned out to be the smallest of the two springs on the throttle assembly. I can't recall if it was on the choke or the throttle gas control arm, but anyway, one end had come out of the little hole that its end hook was controlling. I took it to the shop and the guy found it, repositioned the hook end, in about 2 minutes...didn't charge me anything and I felt kinda bad for wasting his time on something I had overlooked that was right in front of my eyes.

[Deleted]

How did you clean the carb? Just a carb cleaner spray?


If so that don't work anymore, all carb cleaner today is low VOC. It needs to be put through a ultrasonic cleaning machine, with the jets removed.
You can use a gallon dip style carb cleaner, like gumout or hydrosol 2 (sp). Let it sit in it for a day, then spray with carb cleaner. The problem with this, you will need a new gasket set.

[Deleted]

I've had good luck using Lucas Fuel treatment.

I had bought a motorcycle that had been sitting for over 7 years, it ran but poorly. Added Lucas to the fuel, drove it around for a couple of hours, let it sit for a week, and with the same fuel it ran great. I couldn't believe the difference.