I got a 2004 Z400. I put a big gun race exhaust, K&N filter, and a K&N jet kit on it. I ride at 5000 feet and above, and the instructions said I should run a 146 main jet, turn the air screw out 3 turns, and said where to put the needle. I did all that and got it back together, started it and I cannot get it to idle down. It is probably turning 2000 RPMs. I can turn the idle screw all day long with no results. I have had it apart at least 5 times, even put all the stock parts back in it with no change. I checked the rubber intake for a rip or not sealing good, for a vacuum leak, but it looks good. Please help me. I have also removed and replaced the airbox lid to see if that did anything with no change. Easter is coming up and it is the biggest weekend of the year for me. Need this thing running.[img]i/expressions/face-icon-small-confused.gif[/img]

 

If the problem youre having is at idle, then your problem is probably either the mixture screw, pilot jet, or the idle adjustment. Another possible culprit could be the throttle cable. It is adjustable at the throttle and at the carb. I had my carb off once and accidently adjusted the throttle cable too tight, causing a high idle- just back it off at thumb throttle-pull the rubber boot off, loosen the stop nut, and adjust until you get a smooth idle. I pulled my hair out until I figured that out. If you took the carb totally off the bike, this is probably your problem. You want a little bit of free play in the thumb throttle (about 1/8 to 1/4 in.) Hope this helps- PM me if you have any more ????

 

by the way i belive you have to turn the adjuster counter-clockwise to loosen the cable.

 

You called that one. All I had to do was adjust the cable at the thumb throttle. Took it out and rode it down the street and it seems to be running better than it ever has. Thank you so much for your help!

 

like i said-been there done that- if you have any other ?? just PM me- z400 jetting has been a sore subject on this forum and people like to get a little unfriendly when you ask too many ????'s Glad to hear that fixed it though