jetting help

[LTZ400rider]

i have a z400, open lid no snorkel and a k&n pro flow. the stock jet is a 130, so i tried a 147.5 way too rich. tried a 140 still too rich, then i tried a 135 still too rich. ok the next size down is a 130 which is stock. im wondering if i missed a vacuum line or messed the slide up inside. everything seems to go fine until i get to half throttle and it starts boggin from there up, it wont idle either, i have to give it gas for it not to stall, and the idle adjustment is fine. any suggestions?

[cals400ex]

how can you prove that is too rich?

[LTZ400rider]

pull the choke it gets worse, put the airbox on its worse, black plug, etc etc

[cals400ex]

if you pull the choke out, it should get worse. if you put the air box lid on, it should get worse. these are not indications that the bike is rich. when is the plug black? is it after the bike has been sitting? after idleing? after just cruising around?