Oh for the days when the Brigs had a carb with a fuel/power adjustment screw to set how much fuel she got grrrrrrrrrrrrr

I have a Husky Zero Turn with a Kawasaki Twin V 21 which I think is 25 HP.....Recently she began starving for fuel, you know, bad idle cuz she hunts and the govenor keeps revving her back up,,,,,,,,wont run right wide open or when mowing unless you have the choke maybe 1/4 to 1/2 out, Im sure yall get the picture???

I already tried the easy stuff, checked cleaned n blew the fuel lines on BOTH sides of the filter and fuel pump n she has good clean flow there,,,,,,,,gumout down into the carb via the inlet fuel line,,,,,,,gumout via the carbs air intake,,,,,,,air n clean n gumout in the lines and carb inside n outside to the best extent WITHOUT removing the carb (looks like a 2 barrell).......

BUTTTTTTTTTTTTTTT I cant find any external adjustment screws such as the power/fuel adjustment in the bowl or venturi etc area ANYWHERE GRRRRRRRRRRRRRRRRRRRR Its the kind of problem where in the old days you would simply turn the fuel screw out 1/4 turn and no more leaning out problems

Ive heard somethign about valve lash adjustments on those overhead engines but it seems more like I need to turn the power/fuel 1/4 turn out BUT THERE IS NONEEEEEEEEE

Please help meeeeeeeeeee

Ol John T and all

John, Hope you get more of a response than I did.

I suspect there is no adjustment. I've had a few smaller engines with no carb adj. I guess the theory is that if there are no adjustments there is nothing to get out of adjustment. Of course the fact that it's cheaper to manufacture that way, hence more profit, may enter into the equation. Ya think?

Probably right about the cheaper way to make them, it costs to add that screw and adjustment. Yep the responses are settin the world on fire lol. A dude over on YT Mag suspects a vacuum leak is sucking air (leaning her out) and Im gonna take a look
by spraying carb cleaner or WD 40 etc all around where carb mates to manifold etc same as I do on the old John Deeres, if she speeds up and/or smooths out I FOUND THE LEAK,,,,,,,,,,,,

JT

Used to use that technique for vacuum leaks on the ultracentrifuges I serviced except we usually used acetone. Amazed I didn't blow some lab, and me, into the last century.

Been a while since you worked on a lawn mower engine, John T? They quit making it easy years ago. First the high idle adjustment, then the low idle screw went bye-bye. All emissions requirements I guess.
Anyway, I haven't worked on that model yet, but the typical Kawasaki uses a Mikuni carbruetor. The models I have worked on, with this symptom, had a tiny partical in the pilot jet in the top of the body. Yours may be totally different, but I think a disassembly and cleaning will be the answer. I have the clipped ends of a set of ultra light guitar strings to run thru those little holes. The .009" worked for me. You'll have some banjo clips that will work even better, yes? (yeah I know you ain't supposed to do that!)
Mikuni really makes a great carb., in my opinion, but the circuits are complicated, and the jets are numerous and have the tiniest holes. A component tech. manual would be a wise investment.
I'm surprised that one doesn't have the throttle body fuel injection. I don't know anything about those.

tommyhawk

i agree with tommyhawk, the orifice on the pilot jet on those mikumis is very small. i might add that the pilot screw on those mikunis is hidden under a cover to keep people from adjusting it thus keeping the emission people happy. another possibility is that the diaphragm holding the sliding needle could be torn thus the needle is not moving from its seat as it should , if it is the diaphragm piston, sliding needle type carb.