98 yz400 idle problem


5 replies to this topic
  • mpowers

Posted April 20, 2006 - 07:11 AM

#1

clean carb acc pump clean everything set right, idle screw is at the max to get it to idle,fuel screw set a little over 1.5 turns. btw I installed a zip ty fuel screw and tried to start...no go. took it apart and the fuel screw had broken off in the carb. not fun trying to get it out but its out. I sent it back to zip ty and haven't heard back yet.

  • Butta

Posted April 20, 2006 - 08:26 PM

#2

clean carb acc pump clean everything set right, idle screw is at the max to get it to idle,fuel screw set a little over 1.5 turns. btw I installed a zip ty fuel screw and tried to start...no go. took it apart and the fuel screw had broken off in the carb. not fun trying to get it out but its out. I sent it back to zip ty and haven't heard back yet.



Ok, so what exactly are you asking???

:thumbsup:

  • mpowers

Posted May 08, 2006 - 01:28 PM

#3

why wont the idle come down?

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  • DRH

Posted May 09, 2006 - 02:22 PM

#4

Is this when warmed or while cold? Does it idle with the choke out? then dies when the choke is pushed in? How does it run otherwise? I would check two things. The first obvious is the fuel screw. I would also check the hot start valve to make sure it is sealed when not used. These little gems corrode easily from cleaning. Two ways to check the valve is one, plug the end of the hose leading away from the valve or remove the vlave assembly and blow into it. If air can pass through by blowing into it then you have a leak.

  • mpowers

Posted May 14, 2006 - 09:55 PM

#5

it will idle both warm and cold, it runs fine but it just seems wrong to have the idle adjusted all the way "in". I did find that the hot start plunger rod is bent...not sure about the thing leaking I will check it. Got my new zipty screw today and will get it in and try to get it dead on......thanks

  • VOODOOCHILD

Posted May 19, 2006 - 12:35 PM

#6

My 98' YZ400 is having the same problem, except mine will not idle at all. My idle is all the way in as well. I'm getting ready to check the hot start. I've tried my fuel screw in various positions with little or no affect. When I ride, it is popping on decel. I have new gaskets for the exhaust on order. If you figure out your problem please send me your info. It might help me too. Thanks.





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