00 wr400 carb problems


14 replies to this topic
  • Stuart1995

Posted November 09, 2014 - 01:35 PM

#1

okay so im trying to get this wr to run after sitting for about 8 years. i cleaned the carb out totally put new orings in the middle body.

 

after that couldnt get it to run tried kicking and pulling it behind the truck. didnt really want to run.

 

i pulled it apart again today found one of the orings got cut ( they were way too small when i put them in had to stretch them out a bit) i put the piece of oring back together made sure all the others were good. 

 

i put the needle jet at 1.5 turns out.

 

took it back out couldnt get it to kickstart. pulled it behind the truck and held it at about 1/4 throttle and she started and ran. took it out on the road ran her a bit went to turn around i shot the clutch in and tried to go to first and shit stalled. 

 

i tried to get it kick started wouldnt do nothing. pulled the hot start she fired up and didnt run long enough for me to reach down and push it back in. so i pulled it behind the truck again same thing. crack the throttle open and she starts and runs no problem get back to the house shoot the clutch back in and held the throttle open a bit ran fine. as soon as i close it she cuts off. 

 

also some info on the bike. it has the cams advanced to yz timing and a pipe thats pretty much it as far as the engine goes.

 

 

Now for the questions.... imo the needle needs to come out a bit more. what do yal think? i have it at 1.5 turns out now

Does the idle screw (black knob) need to be set for it to idle or will it idle with out it being screwed in?

 

 



  • Ro9

Posted November 09, 2014 - 02:58 PM

#2

Yes, the idle screw need to be set for it to idle! ;)
Get it started, then set the idle to ca 1800 rpm.
Now you can try to figure out the air mixture.
1,5 turns out may not be Rich enough. Mine is 2,5 turns out, on a wr400f -99 With a wr450f -05 carb with the grey wire mod done, and the full Power throttle stop screw! ;)

  • RMK800

Posted November 09, 2014 - 03:20 PM

#3

Replace the jets if the bike has been sitting that long. Especially the pilot jet. Should be around two turns on the fuel screw.

  • Stuart1995

Posted November 09, 2014 - 03:33 PM

#4

Okay cool i wasnt sure if it had to be set or not and ill open the fuel screw up a hair and see what happens. My uncle (who im buying it from) said it probably needs new jets anyway since the advanced cams and fmf pwrcore

  • Krannie McKranface

Posted November 09, 2014 - 05:22 PM

#5

Yes, the idle screw need to be set for it to idle! ;)
Get it started, then set the idle to ca 1800 rpm.
Now you can try to figure out the air mixture.
1,5 turns out may not be Rich enough. Mine is 2,5 turns out, on a wr400f -99 With a wr450f -05 carb with the grey wire mod done, and the full Power throttle stop screw! ;)

 

 

1. You do not set the idle first, you set a base line on the fuel screw first

2. it's not an air screw, it's a fuel screw

3. any thing past 2.5 turns means a lean pilot.

4. once you have the correct pilot jet size, you should be able to kill the motor with 0 turns out

 

You first get the motor HOT

Then you set the fuel screw to 1.0

Then you start the motor and LOWER the idle as low as it will go'

Then you turn the fuel screw out to RAISE the idle

If it goes too high, lower it with the idle screw, and try to raise it again with the fuel screw.

Once the idle is where it's supposed to be, listen to how fast the idle drops when you blip the throttle.

You adjust the fuel screw now, in 1/8 turns to find the fastest idle drop

 

If you start with the idle correct and the fuel screw incorrect, you usually end up with hanging idle by trying to over compensate for a slide that is too high



  • Stuart1995

Posted November 10, 2014 - 03:31 AM

#6

So basically my only problem was i didnt have my idle screw in... -__-
Well ill go over and work on it today after work and let you guys know the results

  • Stuart1995

Posted November 10, 2014 - 08:16 AM

#7

Also what does the hot start do? Just curious first time ever playing with this big of a bike

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  • Krannie McKranface

Posted November 10, 2014 - 10:59 AM

#8

Adds cool air to the combustion, since 4t bikes rum much hotter that 2t...........it's for when you stall it.



  • Stuart1995

Posted November 10, 2014 - 11:06 AM

#9

Okay so that explains why it would fire when i pulled it out and tried kickstarting it

  • Krannie McKranface

Posted November 10, 2014 - 11:57 AM

#10

 If it helps starting when the motor is cold, when using the choke, you power jet is too big.



  • Stuart1995

Posted November 10, 2014 - 05:27 PM

#11

No it was hot when i tried starting it and it just fired and died I imagine all of this is because the of idle screw -__- didnt get a chance to mess with it today though

  • Stuart1995

Posted November 13, 2014 - 03:18 AM

#12

played with the bike last night got her running and idling. i have the fuel screw out around 2.5 turns and i can drop the idle down nice. i was scared at first cause i noticed the head pipe start glowing (it was dark out) but i read this was normal and after cruising it around the yard it got to where it was only glowing right at the head. 

 

i do have some idle hang and a bit of bog if i crack the throttle real quick but after the bog it revs and tachs out real quick. 

 

i think i will order a jet kit and see what i can do to play with it and make it better. 

 

forgot to add that there is a whole lot of cracking going on i believe to goes back to a lean condition? 


Edited by Stuart1995, November 13, 2014 - 03:30 AM.


  • Krannie McKranface

Posted November 13, 2014 - 07:23 AM

#13

Stil have to clean the carb, service the hot start, replace worn parts (slide plate, needle jet), and jet it properly



  • Stuart1995

Posted November 13, 2014 - 08:49 AM

#14

Carb is clean ive had it apart about 3 times now cleaning it. I wouldnt say thing are worn really bc it hasnt been rode much in its life. But i did notice some pitting on the jets and i would like to replace and richen them up a little. What jets would u recommend for a bike with the mods it has. Im going to do a few of the free mods before i do any jetting.

  • Stuart1995

Posted November 17, 2014 - 07:10 AM

#15

Seems like i have a lean pilot i have to have my fuel screw backed out around 3 turns to get it to start consistent and not stall when throttle is applied. I have alot of bog though




 
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