Motorcycle World
Results 1 to 11 of 11

Thread: drz400s jetting

  1. #1
    Ross
    Guest

    Post imported post

    i opened up the airbox and installed a #140 and 25 jets and dyno jet needle on 4th clip from top. I t goes like stink ! Mid range is a lot stronger. I feel like I use 1/2 throttle where I used to go full throttle but.... it misses at half throttle to full throttle worst at about 110km in top gear. top speed is up from 137 to 144km/hr. sea level

    How do your bikes run with the mod ? I guess I'll have to do plug chops to see if its lean or rich . I guess one clip,up or down might fix it.

  2. #2
    beevel
    Guest

    Post imported post

    I have that same miss at 110-120km per hour, full open it runs fantastic. I have determined that I am lean on the needle and will be putting the little dynojet washer into my needle config to give me an equivalent 4.5 needle slot or actually fully go to slot 5.

    I know this will work because I taped over half of my airbox hole and it cured the 110km/h miss. Try it and let me know if it solves your problem.

  3. #3
    Ross
    Guest

    Post imported post

    I raised the needle 1 clip. it might be better, maybe not. It surges with steady 1/2 to 3/4 throttle fairly high rpm. Its o/k under acceleration full throttle or part throttle at lower rpm. The surge is like on for 2 seconds off for a second on for 2 misses a beat on for a second misses a beat on for a second off for 1/2 second etc. I did a plug chop, I'll open it up tomorrow and have a look. gotta take tank off to check plug ! gotta take seat off to take tank off, gotta take sidecover off to take seat off, gotta take bolts off rear rack to take take side cover off. f...k its hard to work on !

  4. #4
    Ross
    Guest

    Post imported post

    Jessee at kientech.com said to put the 142 back and go to the4th clip on the needle. The stock jet, 142.5 works great. The 140 was too lean with opened airbox and the dynojet needle, even on 5th notch. The surging is gone and the motor is probably running cooler. It may be too rich for higher altitudes but the 142.5 seemsperfect on the 4th notch.

  5. #5
    beevel
    Guest

    Post imported post

    you have the dynojet kit correct? I haven't done my needle change yet, but I think I will do the same as you and put my 142.5 main back in.

    Besides then I won't have to pull my carb as I can reach the main jet from underneath.

    Thanks for the info.

  6. #6
    Ross
    Guest

    Post imported post

    I thought you have to pull the carb to change the main jet ?

    You don't have to pull the carb to change the needle. Just loosen all 3 clamps and twist it right to loosen the right screw and twist a bit left to pull up the slideand needle. I found it a bittricky to get the needle back down the little jet outlet thingamajig without having access from carb intake.

  7. #7
    beevel
    Guest

    Post imported post

    Nope, I can actually change everything jet and needle with the carb in place. I don't like doing the needle with the carb in place because with the luck that I have I would drop and lose the little oring that is under the diaphram cover.

    The main jet is actually not to difficult, replace the cheesie philips screws with alan head screws, remove the voltage regulator or whatever that finned contraption above the countershaft is and voila relatively easy access. I guess loosening the clamps and rotating the carb would make it a little easier but hey my method works. 142.5 main jet worked for me as well.


  8. #8
    pancho del rancho
    Guest

    Post imported post

    I got a oh five dr.z sealevel to 5k opened the airbox 3x3 and Dynojet jetted tho wants togo rips but surging the same as yalls had. Planning to go back stock main to 142.5 at 4 clips for like said sealevel Bellingham but now how what say ye about the pilot?twhat pilot you running?etc...

    Hows it working on with the carbueretero yet attached? what's up...

    where' you riding? Island, Squamish area, Vedder, where's good for the solo camper/climber/get-the-f..k-out padre especialista? Some herbs and a gitfiddle be nice... surfing out south on the island, nice breaks and some cold ass water, but clean.

    At Your Liesure but soon...

    Estey









  9. #9
    Ross
    Guest

    Post imported post

    The stock 142.5 takes the surge away, near sea level. I have surging at slightly cracked throttle with the 25 pilot.i am going to try the 27.5 pilot.

  10. #10
    DSBC Participating Member malachi's Avatar
    Join Date
    Oct 2004
    Location
    Victoria, British Columbia, Canada
    Bike(s)
    04 DRZ400, 08 RM125, 91' RM125
    Posts
    590

    Post imported post

    pancho del rancho wrote:
    I got a oh five dr.z sealevel to 5k opened the airbox 3x3 and Dynojet jetted tho wants togo rips but surging the same as yalls had. Planning to go back stock main to 142.5 at 4 clips for like said sealevel Bellingham but now how what say ye about the pilot?twhat pilot you running?etc...

    Hows it working on with the carbueretero yet attached? what's up...

    where' you riding? Island, Squamish area, Vedder, where's good for the solo camper/climber/get-the-f..k-out padre especialista? Some herbs and a gitfiddle be nice... surfing out south on the island, nice breaks and some cold a** water, but clean.

    At Your Liesure but soon...

    Estey
    holy crap....can we say grammar/spelling check
    that was painful to read.....







  11. #11
    pancho del rancho
    Guest

    Post imported post

    holy crap....can we say grammar/spelling check
    that was painful to read.....
    It is indeed painful, and my apologies.I can't even read my own garble..

    Thank you for sharing your jetting experience, Ross. I'll keep future postings brief and legible. By the way, have you tried the 27.5 pilot yet?

    Most Appreciative,

    Brian

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •