Kohler 19hp with Nikki surging

[Freddie21]

Ok Gents, what's my problem (the engine's problem). Kohler SV590 19 hp single, new to me with carb off. I installed the carb and it ran great as I did other repairs on the mower for a month, or so. It started to surge, one day, so I replaced the carb gaskets, filter, fuel line to tank and blew out the tank. New fuel. Same thing, so I soaked the carb, cleaned with wires, air and carb cleaned. No change. Different carb, same surging at all speeds. Will smooth out if 80% choke. Sprayed cleaner around carb and no changing of surging.

Normally, I would suspect the carb, but identical between the two. If I hold pressure against the throttle rod, at any speed, it runs smoothly. Neither the throttle\choke assembly nor the governor have been played with. It all appears to be free and lots of pressure against the throttle at full open position. These are true Nikki carbs. Help!

 

[StarTech]

Anytime you remove a carburetor you must do a static governor adjustment once it is reinstall. Even then a few have governor weight wear that requires a little tweaking like some the engines I do here that a .010 feeler gauge is use to set the adjustment.

 

[Freddie21]

The only governor adjustment , that I am aware of, is the governor shaft to the arm outside the engine. How is the static adjustment done. This is the first of this I've heard in doing a carb replacement.

 

[Freddie21]

I just watched a video on this. I'll try it and let you know. Thanks

 

[Freddie21]

Thanks to all that provided suggestions. I got it licked by backing the idle mixture screw out 2.5 turns. This engine runs great now. But, I run into this constantly and will keep these all in mind. Especially, the governor adjustment. Wouldn't think a carb replacement would require it, but I will try.