Snapper Pro/ Kawasaki FH721V engine

[wb9uze]

I bought this mower new about 8 years ago. It has been WELL maintained. I have NEVER had a minutes trouble with it except this spring the starter solenoid was not kicking in the starter once in awhile but about $6 and a Stens solenoid fixed the problem, also the battery was getting flaky so it got a new super duty battery. Can you imagine that..It was probably on the order of 9 years old or so (thanks to the Deltran Battery Tenders Plus I use)!! I noticed a couple of weeks ago the idle was a little ratty, pretty much ok but like I said just not quite smooth. I found if I would push a little choke on it would smooth out pretty good. Ahah!!, gas mixture prob or not enough gas to the engine on idle. Further investigation showed higher rpm's on the engine "seemed to help" some there too but if I pulled throttle back to idle it was a little rich for that choke setting. I pulled some maintenance and changed the hydro oil with Valvoline Synpower 20w50. Used new 10 micron filters and sucked all the oil out of the tanks and filled the new filters with oil. I also replaced the gas filter and spark plugs. Air filters are good. Hydro units are fine. Just that darned little bit of not quite smooth idle. I had the same thing happen awhile back on my John Deere 240 with a 14HP Kawasaki and adjusting the carb idle air screw it took care of the idle fine and is still good. I think I'm looking at (1) possible problem with the electric fuel pump (original pump). (2)adjusting the carb idle air screw (if I could find one). I hv FH721V shop manual and there is an adjustment for the idle speed but no reference to an idle air/fuel mixture screw on the carb. I'm convinced there is something awry in the carburetor or fuel pump. The amount of gas in the gas filter also never fills the filter up..ie: only about "1/3 to 1/2" full in the filter. What say you and what would you all suggest for me to do to cure it? THANKS, Rex S.

 

[Rivets]

I would start by finding the pilot screw plug and remove it. Under it you will find the pilot screw, which I would back out 1/8 turn and see if it solves the problem. Might have to do it twice. If this does not solve the problem, I would disassemble, clean and rebuild the carb. Your manual has a good description on how to do this. If adjusting the screw solves the problem, use a little silicon sealer to cover the pilot screw.

 

[wb9uze]

Engine manufacturers are getting pretty sneaky anymore but I think I smell the EPA sticking their noses in where one cannot find an idle adjustment screw or it doesn't exist any longer. I'll try to find a rubber plug somewhere on the carb and see if it has that mysterious idle screw hidden. Messing with the carb on the FH721V could be a pain, at least on the Snapper Pro since there are a few things in the way to remove. But maybe I'm just getting tired and lazy. Thanks for the input.

 

[Rivets]

Pages 3-26 & 3-27 of this manual might help you.

http://www.mymowerparts.com/pdf/Kaw...SAKI-SERVICE-REPAIR-MANUAL--99924-2078-01.pdf

 

[wb9uze]

Thanks for replies. Looks like there is no external idle air/fuel mixture screw adjustment that I can find.