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Help CBF250 carb question help

Discussion in 'Honda 250cc Singles' started by Jimmycc, Mar 2, 2017.

  1. Jimmycc

    Jimmycc Active Member

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    hi I have a problem starting and tick over on a cbf250 ,it need a little throttle to start and struggles ticking over until warm,ive noticed there is no valve court of air attached,which is located just behing /side ofthe throttle cabels,and is held to the carb by 2 bolts, could this be causing the problem ??? any help would be highly appreciated jim
     
  2. Murdo

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

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    If there is no valve there, could it be sucking air and causing a too lean condition?
     
  3. Jimmycc

    Jimmycc Active Member

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    Think that's gonna be the case pal. Where the hell will I get 1 of those things from ?? , it's a cover, diaphragm n bits , don't think a breaker will split a carb , do ya know anyone on here who has a carb ??
     
  4. Murdo

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

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    Sorry, no.
     
  5. TechHeadFred

    TechHeadFred Well-Known Member

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    You might have to track down the missing parts new. I've used http://bluecitymotorcycles.com.au for replacement parts for my cbf250. Service was great and their pricing was reasonable.
     
  6. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

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    Shipping to UK might be a killer though
     
  7. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

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  8. TechHeadFred

    TechHeadFred Well-Known Member

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    Whoops, didn't think of that! In that case I've found www.cmsnl.com to have a lot of parts and vaguely reasonable pricing (even including shipping) or a UK Honda parts dealer.
     
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  9. Jimmycc

    Jimmycc Active Member

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    hi please help I cant see where the fuel pipes go on the cbf250 ,ive looked on the workshop manual, where does the pipe from the court of air valve go, it looks like just at front of carb near cylinder head but theres a pipe there that goes up to a breather thing just above carb ?? hope that makes sence
     
  10. TechHeadFred

    TechHeadFred Well-Known Member

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    I'll have a look at mine and see if I can figure out what you mean.

    If you can post a photo it would help.
     
  11. Jimmycc

    Jimmycc Active Member

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    HI TECH HEAD,THANKS FOR REPLY,I RECENTLY PURCHASED AND CHANGED ENGINE ,I CANT GET MY BIKE TO TICK OVER OR START WITHOUT THROTTLE,I NOTICED THERE WAS NO BLOCK ON SIDE OF CARB,-COURT OF AIR-MISSING SO PURCHASED 1 WHICH WAS QUITE EXPENSIVE AT 120 SQUIDS HOPING IT WOULD START NORMAL, I LOOKED AT THE WORKSHOP MANUAL AND AS FAR AS I CAN SEE THE PIPE COMES FROM THAT BLOCK-COURT OF AIR- OVER TO THE VERY FRONT OF CARB(NEAR THE CYLINDER HEAD) but there was a pipe connected to the front of carb that went up to a block just under tank ???? I took it off and left that with nothing attached, and put the pipe to the front of carb,expecting it to run fine but still the same ,I cant put a picture on but have part number 16048-kpf-961, any chance of drawing me a diagram of where your pipes go buddy coz im at my wits end ,ps no idea what that block is just under tank cheers jim
     
  12. TechHeadFred

    TechHeadFred Well-Known Member

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    Hi Jimmy,

    I've had a look at mine and been reminded that I have a broken "Y" piece in the air lines.

    From right side of bike:

    7cab6bab2beba5a49e713f5d6c0edbaf.jpg

    From left side of bike:

    de4fa2106724be3f259a0b30d2946f69.jpg

    I'll try to find a diagram of how they are supposed to connect, or I'll draw you one tonight (my time).

    Unfortunately the English workshop manual is badly translated from Portuguese, so the "court of air" is not helping to identify the missing part. I'll have a look at my copy and a oats diagram and see if I can make some sense of it for you.


    As a side note, writing in capital letters is considered rude online, as it is difficult to read and comes across like you are shouting.
     
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  13. TechHeadFred

    TechHeadFred Well-Known Member

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    *parts diagram

    Stupid phone!
     
  14. Jimmycc

    Jimmycc Active Member

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    hi tech, it's not the bottom pipes it's the one at the offside of the carb where the accelerator cables are and clutch cable, its no 9 on the diagram on earlier posts. Cheers jim
     
  15. TechHeadFred

    TechHeadFred Well-Known Member

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    Ahhh, no problem.

    I'll have a look through my copy of the manual and my photos from when I did the tank swap on my last one when I get home from work in a couple of hours!
     
  16. TechHeadFred

    TechHeadFred Well-Known Member

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    Looks like part #9 is the air cut off valve set (court of air = cut off air?).

    Looks like I don't have any pics of the carb without the tank on, will have a proper look for one that shows how it connects after work.
     
  17. Jimmycc

    Jimmycc Active Member

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    Thanks tech ,
     
  18. TechHeadFred

    TechHeadFred Well-Known Member

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    Hi Jimmy, I think this might be what you're looking for?

    upload_2017-4-4_18-58-3.png
    It looks like the hose connects from the air cutoff valve (on the left in the pic below) to the nipple at the bottom (below the black arrow)

    upload_2017-4-4_18-59-10.png

    I hope this helps?
     
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  19. Jimmycc

    Jimmycc Active Member

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    Hi I'm sure that's right , I put on but has made no difference to the starting. Bear with me I'll have a tinker thanks jim
     
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  20. TechHeadFred

    TechHeadFred Well-Known Member

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    Does using the choke make any difference? If so, use the choke and let it warm up for a few minutes. If not, troubleshooting steps are pretty standard - I've translated the ones from the manual's broken English after cross-referencing with another shop manual:

     
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