/ Register

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

Pinned GSX250 - Air Intake - Exhaust - Caburettor Tuning

Discussion in 'Suzuki 250cc Twins' started by GreyImport, Jan 22, 2014.

Page 1 of 3
  1. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

    Messages:
    10,929
    Likes Received:
    6,720
    Trophy Points:
    1,168
    Joined:
    Jun 14, 2012
    Gender:
    Male
    Occupation:
    Between a Rock and a Hard Place
    Location:
    North by NW NSW Oztralia - Tamworth
    My Bike:
    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
    I think if possible starting with a stock setup with the carbs and inlet and exhaust system would be ideal but not always possible , especially with our project bikes.
    It would be a good idea if we all posted our starting points (as in jet sizes , clip heights, pilot screws etc)
    And also what air intake and exhaust system you are implementing ...... photos welcome!

    If you have your carbys apart anytime can u check , and post whats there, and then your changes and successes and failures.
    Please post any relevant articles you find online.
     
    • Like Like x 2
    GreyImport, Jan 22, 2014
    #1
  2. geesex66

    geesex66 Active Member

    Messages:
    35
    Likes Received:
    36
    Trophy Points:
    188
    Joined:
    Jun 29, 2013
    Gender:
    Male
    Location:
    Herne Hill, London
    My Bike:
    Suzuki GSX250
    Great idea. I took loads of pics when I had mine apart, so I'll post them up soon. I need to go back in again to check jet sizes, and needle positon. And to clean the pilot air jet (which I didn't even take out before).
     
    geesex66, Jan 24, 2014
    #2
  3. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

    Messages:
    10,929
    Likes Received:
    6,720
    Trophy Points:
    1,168
    Joined:
    Jun 14, 2012
    Gender:
    Male
    Occupation:
    Between a Rock and a Hard Place
    Location:
    North by NW NSW Oztralia - Tamworth
    My Bike:
    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
    Excellent !
    I havnt had mine out either but when doing the FZR carbs the pilots were very soft brass and the head can crumble very easily , so be careful.
     
    • Like Like x 1
    GreyImport, Jan 24, 2014
    #3
  4. Phil

    Phil Senior Member Contributing Member

    Messages:
    3,613
    Likes Received:
    1,549
    Trophy Points:
    923
    Joined:
    Aug 8, 2010
    Gender:
    Male
    Occupation:
    M C E
    Location:
    Sunshine Coast Qld
    Home Page:
    My Bike:
    Suzuki GT250X7 Kawasaki ZZR600
    I concur with Mr Grey 100%, try and locate the correct size flat head screw-driver that fits perfectly. The heads as mentioned are very soft and damage easily. If the jet won't move, don't force it as you will regret it later. My advise is spray a little lubricant (WD40) or (INOX) or similar and let it penetrate a little, then try again.
     
    • Like Like x 2
    Phil, Jan 24, 2014
    #4
  5. cal

    cal Well-Known Member Premium Member

    Messages:
    587
    Likes Received:
    461
    Trophy Points:
    248
    Joined:
    Aug 17, 2013
    Gender:
    Male
    Occupation:
    Mechanic
    Location:
    Perth, WA
    My Bike:
    Kawa '88 ZXR250A / 86' BMW K100. 1992 VFR400R
    even half a dozen rapid taps on the screwdriver can free up the threads. (this is a finer alternate to an impact driver)
     
    cal, Jan 24, 2014
    #5
  6. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

    Messages:
    10,929
    Likes Received:
    6,720
    Trophy Points:
    1,168
    Joined:
    Jun 14, 2012
    Gender:
    Male
    Occupation:
    Between a Rock and a Hard Place
    Location:
    North by NW NSW Oztralia - Tamworth
    My Bike:
    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
    • Like Like x 2
    GreyImport, Jan 24, 2014
    #6
  7. geesex66

    geesex66 Active Member

    Messages:
    35
    Likes Received:
    36
    Trophy Points:
    188
    Joined:
    Jun 29, 2013
    Gender:
    Male
    Location:
    Herne Hill, London
    My Bike:
    Suzuki GSX250
    I had no problems with any threads or screws. The main jets unscrewed very easily and the brass was new and hard. The manual says that the needle jets should just fall out when you tune the carby upside down, but mine were tight. I had to encourage them out with some gentle tapping. I guess that confirms my jets were not the original stock ones.

    BTW I found this video useful when trying to understand how all the various components work together to make the engine run

     
    • Like Like x 5
    geesex66, Jan 28, 2014
    #7
  8. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

    Messages:
    10,929
    Likes Received:
    6,720
    Trophy Points:
    1,168
    Joined:
    Jun 14, 2012
    Gender:
    Male
    Occupation:
    Between a Rock and a Hard Place
    Location:
    North by NW NSW Oztralia - Tamworth
    My Bike:
    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
    Good stuff .... that vid is excellent.

    Can u post what jet sizes u have?

    cheers mate
     
    GreyImport, Jan 28, 2014
    #8
  9. geesex66

    geesex66 Active Member

    Messages:
    35
    Likes Received:
    36
    Trophy Points:
    188
    Joined:
    Jun 29, 2013
    Gender:
    Male
    Location:
    Herne Hill, London
    My Bike:
    Suzuki GSX250
    Yeah I've just got the carbies off again. And the airbox. Probably the most frustrating thing I've ever done... had to cut it into three pieces with a hacksaw. I guess its not going back in. I'll get into the carbies tomorrow evening
     
    geesex66, Jan 28, 2014
    #9
  10. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

    Messages:
    10,929
    Likes Received:
    6,720
    Trophy Points:
    1,168
    Joined:
    Jun 14, 2012
    Gender:
    Male
    Occupation:
    Between a Rock and a Hard Place
    Location:
    North by NW NSW Oztralia - Tamworth
    My Bike:
    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
    Cant remember reading that in the manual

    :lolsign:
     
    • Like Like x 1
    GreyImport, Jan 28, 2014
    #10
  11. geesex66

    geesex66 Active Member

    Messages:
    35
    Likes Received:
    36
    Trophy Points:
    188
    Joined:
    Jun 29, 2013
    Gender:
    Male
    Location:
    Herne Hill, London
    My Bike:
    Suzuki GSX250
    OK so I've got the jets out of one of the carbies. I can't read the numbers! They're so small I can't even tell which way up they are... my eyes aren't what they used to be. So tomorrow I'll take them into work and see if anyone else can decipher them. Also I have a macro setting on one of my digital cameras; charging the battery tonight
     
    geesex66, Jan 29, 2014
    #11
  12. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

    Messages:
    10,929
    Likes Received:
    6,720
    Trophy Points:
    1,168
    Joined:
    Jun 14, 2012
    Gender:
    Male
    Occupation:
    Between a Rock and a Hard Place
    Location:
    North by NW NSW Oztralia - Tamworth
    My Bike:
    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
    • Like Like x 3
    GreyImport, Jan 29, 2014
    #12
  13. Phil

    Phil Senior Member Contributing Member

    Messages:
    3,613
    Likes Received:
    1,549
    Trophy Points:
    923
    Joined:
    Aug 8, 2010
    Gender:
    Male
    Occupation:
    M C E
    Location:
    Sunshine Coast Qld
    Home Page:
    My Bike:
    Suzuki GT250X7 Kawasaki ZZR600
    • Like Like x 1
    Phil, Jan 29, 2014
    #13
  14. Murdo

    Murdo The Good Doctor Staff Member Contributing Member Ride and Events Crew

    Messages:
    6,400
    Likes Received:
    4,788
    Trophy Points:
    1,148
    Joined:
    May 4, 2013
    Gender:
    Male
    Occupation:
    Retired
    Location:
    Tamworth, NSW
    My Bike:
    1937 Royal Enfield 250, CF Moto 250 V5, Honda's XL250, CBR250, FT500 plus a few others.
    Good for looking down into plugs to see the mixture colours too.
     
    • Like Like x 1
    Murdo, Jan 30, 2014
    #14
  15. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

    Messages:
    10,929
    Likes Received:
    6,720
    Trophy Points:
    1,168
    Joined:
    Jun 14, 2012
    Gender:
    Male
    Occupation:
    Between a Rock and a Hard Place
    Location:
    North by NW NSW Oztralia - Tamworth
    My Bike:
    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
    Ahh yes I remember seeing them in the Aust Post catalogue also just after I ordered one !
     
    GreyImport, Jan 30, 2014
    #15
  16. Ben Mulligan

    Ben Mulligan Well-Known Member Premium Member Contributing Member

    Messages:
    261
    Likes Received:
    276
    Trophy Points:
    273
    Joined:
    Nov 14, 2013
    Gender:
    Male
    Occupation:
    Photographer
    Location:
    Chelsea, Victoria
    Home Page:
    My Bike:
    GSX250E Cafe
    I'm about to start rejetting my BS30SS carbies too. Got the new exhaust today and trying to find a Mikuni dealership with various main jet sizes in VIC. Anyone got any ideas?
     
    Ben Mulligan, Jan 30, 2014
    #16
  17. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

    Messages:
    10,929
    Likes Received:
    6,720
    Trophy Points:
    1,168
    Joined:
    Jun 14, 2012
    Gender:
    Male
    Occupation:
    Between a Rock and a Hard Place
    Location:
    North by NW NSW Oztralia - Tamworth
    My Bike:
    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
    GreyImport, Jan 30, 2014
    #17
  18. geesex66

    geesex66 Active Member

    Messages:
    35
    Likes Received:
    36
    Trophy Points:
    188
    Joined:
    Jun 29, 2013
    Gender:
    Male
    Location:
    Herne Hill, London
    My Bike:
    Suzuki GSX250
    So I got someone with younger eyes than me to look at those jets:

    Main jet: 117.5
    Needle jet: 263
    Pilot jet: 17.5

    There's a couple of symbols in there too. Square with a smaller square inside, and another with two vertical lines joined by a 2 on its side
     
    geesex66, Jan 30, 2014
    #18
  19. GreyImport

    GreyImport Administrator Staff Member The Chief Contributing Member

    Messages:
    10,929
    Likes Received:
    6,720
    Trophy Points:
    1,168
    Joined:
    Jun 14, 2012
    Gender:
    Male
    Occupation:
    Between a Rock and a Hard Place
    Location:
    North by NW NSW Oztralia - Tamworth
    My Bike:
    *Kawasaki ZXR250C *Yamaha FZR250R 3LN1 *Yamaha FZR400 *Triumph Bonneville 750 T140V *Triumph Daytona 675 *Triumph Tiger 800XC
    Square with a smaller square inside = Genuine Mikuni logo

    The main and pilot are stock so I guess the needle jet is also ..?

    Theres so many GSXs on this forum .... did u have any changes to the air intake and/or exhaust and was it running ok at any stage? :D
     
    GreyImport, Jan 30, 2014
    #19
  20. Ben Mulligan

    Ben Mulligan Well-Known Member Premium Member Contributing Member

    Messages:
    261
    Likes Received:
    276
    Trophy Points:
    273
    Joined:
    Nov 14, 2013
    Gender:
    Male
    Occupation:
    Photographer
    Location:
    Chelsea, Victoria
    Home Page:
    My Bike:
    GSX250E Cafe
    Those seem to correspond with what the manual was saying. I'm lowering resistance on the pod end but im fixing the exhaust on the other. Going to find a local spot so I can try some jets and get back to you as well
     
    • Like Like x 1
    Ben Mulligan, Jan 30, 2014
    #20
Page 1 of 3

Share This Page