Not a motorcycle...

I am not looking for help with this project but here is what I am into. I have a portable generator, a Generac 4000xl, which wouldn't start last year. Now, I have removed the carb three times and everything is super clean but the emulsion tube is not removable. I don't even know if there are holes in its sides. The machine will run at a low idle but with a load (higher RPMs) it surges non stop. I also reset the intake valve clearance, which was too tight. So exasperating! The only thing left is a possible governor problem. Grrrr.

 

I've watched a bunch of these videos but not this one. The generator was a nice find. I didn't clean the carb with ultrasonic cleaner but might need to because of the emulsion tube issue. I might convert it to natural gas, which would also fix the issue, but would like the gasoline option too. Time to make an ultrasonic cleaner.

 

found this while looking for honda lawnmower surging last summer

 

I did clean the pilot jet. It is located under a panhead screw and is removable once the screw is removed.

 

Surging is pretty much always a fuel issue, too lean cause the motor to stumble and when the rpms drop the governor opens the throttle. It the governor wasn’t working then it wouldn’t surge at all. Some of those carbs are a pain to clean throughly.

I used to work on generac in a shop years ago, I can see if I still have the service manual for that model.

 

Thanks, as far as I can see everything is clean. Only a few items are not removable and the emulsion tube is one. Some carbs have a screwed in tube while others have a plastic tube held in by o-rings. Mine has no way to unscrew and appears to be pressed in. the bottom is open and not blocked by anything so fuel from the main jet can go right up without any need for side holes. I can't find where any fuel would be blocked and that is the dilemma. I can also hold the throttle open and it runs fine at the correct RPM's, but otherwise it surges. That is why I was thinking of a malfunctioning governor.

 

Not yet tested but here is my newly assembled non-ultrasonic vibra-clean. Consists of 1 pad sander, 1 peanut butter pretzel container (emptied), piece of aluminum sheetmetal, leftover threaded rod from YICS tool project, various nuts, lockwashers, screws. Device is shown upside down. Part(s) will sit in the bottom of the container.

 

I looked everywhere, I must've tossed all my manuals during one of the many moves in the last 20 years. Let us know how that works, I still think you are running into a fuel issue but maybe your spring is stretched, incorrect, or attached to the wrong adjustment hole somewhere. The spring pulls the throttle open and the governor will push it closed, its the balance of these two actions that maintain the RPM. Should the motor slow down due to load, the governor will "push" less and the spring will "pull" more to open the throttle to accommodate. If you disconnect the spring, the motor should idle (assuming it has an idle stop and screw, some generators do not) and you should notice that it takes more considerable force to open the throttle when compared to when the motor is not running. I've probably worked on 1000+ small engines during my short career as a lawn equipment mechanic and the only governor issues I can think of were catastrophic and basically came apart internally (Briggs with plastic governor gears come to mind).

There is a procedure to set the static position of the governor, that is mainly why I was looking for the manual. Good place to start.

Good luck and let us know!

 

Got the generator finally working. The linkage rod from governor to throttle had some resistance during travel from idle position to full throttle position. The governor would hit this spot and push past but that caused the governor to actually move too far (over correct), which caused it to correct again in the other direction. Also adjusting the governor spring tension settled it right down to 120V @ 60Hz.