Kawasaki 23hp idle up/down

Working on our 2002 Hustlerz 60". Idles up/dwn, not as noticeable at full throttle. Sonofadocker suggested manifold leaks,cracks in gas lines. Took carb off checked out ok. Is there a carb parts blow up available somewhere. I would like to check out the float bowl,and jets . There were two bolts on bottom of carb with the # 5 stamped on them . Two brass bb's were imbedded by each bolt. Couldn't break loose the bolts. I need to know what they are before I put more effort in them.
Thanks Gatorblade

Iv'e got lookers but no takers so trying to give more info. I usually start the mower on warm days in the winter so I don't treat the gas. Iv'e done this for 10yrs. but maybe something has varnished up. At idle it trys to die then the govener gives it a little gas and it revs up . I can squirt gas in carb, smooths out for a sec. It was suggested I take the bolt from the float bowl and clean the jet. I went to Hustler carb FH680V 23hp. It shows in the picture 2 bolts at the bottom of carb. Even if I could get the bolt out without taking carb off,I would still have to take it off to get the jet out, right? On my old float bowls you take out one bolt in the center drop the bowl, gas comes running till you push up on the float. This new stuff, I don't want to make it worse as it runs pretty good at full throttle. I put a bottle of carb cleaner in gas tank today and let it idle so some would get in carb . Is there anything else I can say to let you help me?
Thanks, Gatorblade

Here is a website that may help. OEM Parts
Two things I would check. Did your throttle control cable move, not allowing the throttle to fully open. Second, If you have a fuel shutoff solenoid on the carb, remove it and spray carb cleaner in there to make sure this passage is open. I don't think you should have to rebuild the carb, I would try using a triple dose of an injector cleaner run through the fuel on your next mowing. (I use SeaFoam) It may take awhile to internally clean.

Sea Foam Motor Treatment is great stuff!! When I get a machine that runs poorly I syphon one tank almost empty, ad some Sea Foam and some fresh fuel so it will get into the carb quickly when started, sometimes I do multiple treatments.
Periodic running doesn't preserve gasoline, only a fuel conditioner can preserve gasoline, and with 10% ethanol in gasoline not all fuel conditioners are effective. I use Star Tron and Sea Foam when I refill my fuel storage jugs.
Mad Mackie in CT

Thanks Rivets and Mad Mackie for your suggestions. When I took out the solenoid I caught the gas in a jar and it did have black pepper type specks in it. Cleaned and re-installed, no difference. I doubled the carb cleaner an mowed for 2 hrs. I'll keep at it! What about the screw beside the solenoid switch, what does it adjust?
Gator Blade

It may be time to replace the fuel line and possibly the fuel pump. Some only get 4-5 years on fuel hose with ethanol gasoline. Some fuel filters soften from the ethanol.