Z400 idle problems

[John DInneen]

OK here is my issue- I have a 2003 Z400 with a LRD full exhaust, K&N filter and Dyno jet. I start the quad with choke, let it warm up, take the choke off and it dies. I have cleaned the carb, removed all jets and cleaned them out. For some reason I am unable to to set the idle and fuel/air mix screw just perfect to keep the quad running. Any ideas??? I've turned the fuel / air screw in and backed it out 2 turns (more like 2.5) and the bike with still not run unless the choke is on, and for reason I'm unable to set the idle just perfect. Any help would be great.

Thanks in advance.

JD in KC

[brian 68]

your float is to low, try raising it by bending the tab that pushes the neddle up shutting the gas off. only move it a little. you could take the carb to a shop and have it set. that would be the easiest, and shouldn't cost that much. if it is ok you could have a burnt intake valve, or a shim that is to tight (on the valve) but rule out the carb first

[JOHNDOE83]

you need a bigger pilot jet!!!

try turning your screw out 3.5 turns and see if it helps.

[John DInneen]

I really dont thik I need a bigger jet. I have had the exhaust and filter for 2 years and last year I never had an issue. I took the carb apart again and cleaned everything, took out the main jet and cleaned it. I also adjusted the float. Put everything back together and the same thing. I turned the fuel/air mix to 3.5 and no change. I adjusted the idle and fould that when I went to move the choke from full to half the quad began to increase in RPM's. When I go to no choke, the quad will not stay running with out assistance from the trottle. Does anyone have more ideas??

[JOHNDOE83]

do you backfire or pop at all when decellerating? thats a pilot jet being to small.

All of what your describing is pilot jet related, the bad idle, cant get it right, stalling off choke, all pilot jet related.

dynojet kits usually only have main jets, not pilot jets?

If you still feel thats not the issue, try cleaning out the needle and ceet, or try blowing out the pilot jet with a air compresor, I can assure you its pilot related....being to lean.

www.jetsrus.com .... go to the FAQs section, they explain it there.

if you have to turn the air fuel screw more then 2.5 or 3 turns, you need a bigger pilot jet....just give it a shot?

[John DInneen]

I'll pull it a part and give it a try. At this point I will take any advise I can get. Do I set the idle first or the fuel air mix. The fuel air mix really doesn't seem to do anything. No increase of RPMs

[John DInneen]

So I pulled teh carb apart again and pulled all the jets, cleaned everything and put it all beack together. And WOOHOO it runs like a dream. I have noticed that i have some dirt or sand in the fuel tank.

Thanks to everyone that has responded to my post on this.

JD

[wilkin250r]

Originally posted by John DInneen
I have noticed that i have some dirt or sand in the fuel tank.

That stuff is almost impossible to clean out completely. Get yourself a small inline fuel filter to keep the problem from happening again. Next problem will be gas coming out the overflow.