After spending winter in garage fuel does
not seem to flow through the ON gate or Reserve.
Prime seems ok.  Will start and rev  but will not idle.
Does the carborator need to be removed to access
and clean out the bowl?  Factory set phillips
head screws allow no leverage.
Thanks  

just go ahead and pull the carb... you'll find it much easier to get a good cleaning with it removed, as the z400 seems to be meant only to be worked on by tiny asian hands, lol. the fact that it wont idle, but will start and rev, tells me that the main cleaning point that you need to concentrate on is the pilot jet hole, and the needle valve. i don't know how good your mechanic skills are, but incase you don't know, your needle valve, is the short fat needle that is moved by your floats. im not talking about the mid-range needle that is moved up and down with your slide on the throttle cable. and your pilot jet will be the jet off to the side of your main jet, this is the jet that controls thelower end of your powerband, which is why i say to concentrate on these areas. by all means, clean the whole carb well, but really inspect those areas. just incase you havent done so already, empty the tank and put fresh gas in the tank before jumping to conclusions about the carb. im a new member to this site, as i only signed up ten minutes ago, just to answer your question, so if you have tried these seps and still have trouble, by all means, please email me @ Bigdaddychaz2516 @ hotmail . com