/ Register

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Help How to adjust fuel mix Zr250

Discussion in 'Kawasaki 250cc In-line 4's' started by Kwakhead, Mar 14, 2022.

  1. Kwakhead

    Kwakhead Member

    Messages:
    23
    Likes Received:
    11
    Trophy Points:
    13
    Joined:
    Dec 23, 2021
    Gender:
    Male
    Location:
    Perth
    My Bike:
    Kawasaki balius
    Hi all,

    Recently my balius has been a little temperamental on cold starts. I believe it’s running rich as I’m getting poor fuel economy and it’s very bogged down until it gets hot, and even when hot it can tend to bog down a little.

    Can I adjust the fuel mixture while the carbys are on the bike, and how do I lean it off a little. Pictures would be of great benefit, I’ve never played with carby bikes before, mostly fuel injected cars.

    Thanks in advance!
     
    Kwakhead, Mar 14, 2022
    #1
  2. jmw76

    jmw76 Well-Known Member

    Messages:
    1,162
    Likes Received:
    596
    Trophy Points:
    498
    Joined:
    Mar 12, 2017
    Gender:
    Male
    Location:
    Melbourne, Australia
    My Bike:
    Honda cbr250rr mc22 road + 1 track, Honda RC 162 tribute bike, Honda Spada Vt250, Honda CBR900RR
    Are you certain it is rich? Pull the plugs out straight after a bit of a run and have a look.
    Post some pics looking down into the plugs with good light behind you.
     
    jmw76, Mar 15, 2022
    #2
  3. DannoXYZ

    DannoXYZ Well-Known Member

    Messages:
    354
    Likes Received:
    216
    Trophy Points:
    248
    Joined:
    Sep 7, 2017
    Occupation:
    IT Manager
    Location:
    Mesa, AZ
    My Bike:
    Honda CB125TT, Kawi EX250F, EX250J race, Honda CBR250RR-MC19, NSR350R-MC21 VF500F, CBR600RR, VFR750F
    There's no single "adjustment", you'll have to identify the throttle*load range you want to adjust. Then modify the component that is responsible for mixtures there.

    [​IMG]
     
    • Informative Informative x 2
    DannoXYZ, Mar 16, 2022
    #3
  4. Kwakhead

    Kwakhead Member

    Messages:
    23
    Likes Received:
    11
    Trophy Points:
    13
    Joined:
    Dec 23, 2021
    Gender:
    Male
    Location:
    Perth
    My Bike:
    Kawasaki balius
    Thanks guys, I will try get it taken apart soon but I’m very shy on time at the moment so may take me a bit. Is there something that may cause it to randomly run rich, i.e. something becoming stuck within the carby?
     
    Kwakhead, Mar 17, 2022
    #4
  5. DannoXYZ

    DannoXYZ Well-Known Member

    Messages:
    354
    Likes Received:
    216
    Trophy Points:
    248
    Joined:
    Sep 7, 2017
    Occupation:
    IT Manager
    Location:
    Mesa, AZ
    My Bike:
    Honda CB125TT, Kawi EX250F, EX250J race, Honda CBR250RR-MC19, NSR350R-MC21 VF500F, CBR600RR, VFR750F
    let's make it simpler. Under what operating conditions is it running rich?

    - idle?
    - steady state cruising @ 100?
    - WOT?
     
    DannoXYZ, Mar 18, 2022
    #5
  6. Kwakhead

    Kwakhead Member

    Messages:
    23
    Likes Received:
    11
    Trophy Points:
    13
    Joined:
    Dec 23, 2021
    Gender:
    Male
    Location:
    Perth
    My Bike:
    Kawasaki balius

    I’m not too clued in on all the signs of running rich. But from what I can tell I think at idle it’s most prominent due to being a bit hard to start and get running. Can be very bogged down in low rpm or low throttle applications, my thinking is when you open up the throttle it’s getting a lot more air in and thus leans it off more.

    It almost seems intermittent because some days it runs great and other days not so. Hopefully that sheds a little light on it.
     
    Kwakhead, Mar 19, 2022
    #6
  7. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

    Messages:
    4,737
    Likes Received:
    2,883
    Trophy Points:
    943
    Joined:
    Mar 18, 2014
    Location:
    Sydney NSW
    My Bike:
    FZR250R 3LN6
    Carbs with plugged pilot jets will run lean. It can be difficult to tell the difference between rich bogging and lean bogging. There are some clues though.

    If the bike is lean, it will struggle to start without choke when cold. This may improve when hot.

    When rich, the bike will start easily with no choke. Adding choke may not do much, or it may cause it to flood and stall out, and then have trouble restarting due to fouled plugs.

    Also, if it starts okay cold and runs fine, but has real difficulty restarting when hot, the valve clearances might need attention
     
    • Like Like x 1
    Linkin, Mar 19, 2022
    #7
  8. Kwakhead

    Kwakhead Member

    Messages:
    23
    Likes Received:
    11
    Trophy Points:
    13
    Joined:
    Dec 23, 2021
    Gender:
    Male
    Location:
    Perth
    My Bike:
    Kawasaki balius
    At the moment it seems to start cold with no choke but I need to add choke immediately to keep it going. If I go full choke it dies completely. So does seem to have some clues of being rich. But I wonder if its worth adjusting the pilot screw of if It won’t yield any results.

    If time was not an issue I’d just pull the carbs off completely and clean them all out. But I don’t have the time at the moment
     
    Kwakhead, Mar 19, 2022
    #8
  9. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

    Messages:
    4,737
    Likes Received:
    2,883
    Trophy Points:
    943
    Joined:
    Mar 18, 2014
    Location:
    Sydney NSW
    My Bike:
    FZR250R 3LN6
    I would inspect and clean the pilot jets first, then reset the mixture screws to factory specs. It's easier to do the latter with the carbs out of the bike.
     
    Linkin, Mar 19, 2022
    #9
  10. Kwakhead

    Kwakhead Member

    Messages:
    23
    Likes Received:
    11
    Trophy Points:
    13
    Joined:
    Dec 23, 2021
    Gender:
    Male
    Location:
    Perth
    My Bike:
    Kawasaki balius

    Sounds like a good idea, do you think I’d need a new seal kit or just use what comes off. And do you know what the adjustment for the pilot is on the balius A. I’ve seen many different options
     
    Kwakhead, Mar 19, 2022
    #10
  11. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

    Messages:
    4,737
    Likes Received:
    2,883
    Trophy Points:
    943
    Joined:
    Mar 18, 2014
    Location:
    Sydney NSW
    My Bike:
    FZR250R 3LN6
    Anywhere from 1.5-3 turns, but as a general rule I'd start at 2.5 turns from lightly seated and adjust as necessary. Might be a good idea to count where they are at the moment for comparison
     
    • Like Like x 1
    Linkin, Mar 19, 2022
    #11
  12. Kwakhead

    Kwakhead Member

    Messages:
    23
    Likes Received:
    11
    Trophy Points:
    13
    Joined:
    Dec 23, 2021
    Gender:
    Male
    Location:
    Perth
    My Bike:
    Kawasaki balius
    Sounds good, I’ll give that a go then. Thanks for the help!
     
    • Like Like x 1
    Kwakhead, Mar 19, 2022
    #12
Tags:

Share This Page