99 YZ400F Pilot Screw


6 replies to this topic
  • zuvee

Posted January 27, 2008 - 10:02 AM

#1

Shouldn't my pilot screw set consist of: Pilot screw, spring, and 2 rubber washers? Thanks

  • grayracer513

Posted January 27, 2008 - 12:12 PM

#2

No. From the bottom, it's:

>the screw
>spring
>brass washer
>O-ring

  • zuvee

Posted January 27, 2008 - 01:48 PM

#3

I couldn't tell on the diagram, but knew there were two types of "washers". I'm missing the brass washer then. Would this cause the bike to start and run on choke only? She will only start with choke run for 1-2 seconds then die. Yesterday She would run all daylong as long as choke was on and I didn't touch the throttle.

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  • todds924

Posted January 27, 2008 - 01:59 PM

#4

I couldn't tell on the diagram, but knew there were two types of "washers". I'm missing the brass washer then. Would this cause the bike to start and run on choke only? She will only start with choke run for 1-2 seconds then die. Yesterday She would run all daylong as long as choke was on and I didn't touch the throttle.


You neeed to clean your carburetor. Pilot jet especially!!!!! It will run like a champ....I promise. And whay do you mean by "2" types of washers???? There is a steel or brass washer and an o ring.

  • zuvee

Posted January 27, 2008 - 02:38 PM

#5

I have cleaned the carb once, father in-law once, and took it to mechanic once. 3 carb cleans, still can't figure it out. By "washers" I meant that according to the diagram I (I use worldofpowersports.com) It shows the screw, spring, and obviously the washer and o-ring, but you can't tell by the picture one is brass and the other is rubber. Would missing the brass washer cause the bike to act like it is?

  • todds924

Posted January 27, 2008 - 02:52 PM

#6

I have cleaned the carb once, father in-law once, and took it to mechanic once. 3 carb cleans, still can't figure it out. By "washers" I meant that according to the diagram I (I use worldofpowersports.com) It shows the screw, spring, and obviously the washer and o-ring, but you can't tell by the picture one is brass and the other is rubber. Would missing the brass washer cause the bike to act like it is?


It could. I would really make sure that pilot jet is for sure clean..You can "see daylight" through it. I couldn't tell yo how many people have come to me and said they cleaned the carb 5 times....only to find the pilot jet plugged solid.You took it to a mechanic and it didnt run right when you got it back?? I would also make sure the slide plate isnt put in upside down. Also, not having the washer on your mixture screw will cause the spring to tear up the o-ring when screwed in. It will ruin the o-ring.

  • zuvee

Posted January 27, 2008 - 03:11 PM

#7

through the screw? I have no light. It is solid everywhere. I have daylight through the pilot JET. All jets for that matter. Thanks





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