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Underpowered Choke?

Discussion in 'Technical and Troubleshooting Torque' started by Toyboy, Nov 1, 2010.

  1. Hey guys,

    Please remove this thread and direct me to one already outlining this problem if it exists. I tried to search for it but came up with nothing.

    On my trusty old CB250 I've encountered a problem with my choke. It used to rev easily up to 3000 or so if I pulled it merely half out or so. Now however, I pull it out the whole way and it struggles getting up to 2000 revs.

    What could be causing this underpowered choke problem?
  2. crap in the carb? does it rev poorly under throttle too or just under choke?
  3. It revs easily with the throttle. Just the choke is struggling it seems.
  4. only thing i can think of is maybe the choke isn't opening properly
  5. When is the last time you had it serviced ?
    could be as simple as a partially blocked air filter, making it run way too rich.
  6. I assume it is happening on startup, not after it has warmed up?
  7. It was serviced a little over a month ago.

    And yes, on startup. But even when it does warm up it doesn't hit the heights that it did when I first got it. It hovers around 2000 fully open when it used to do that half open.
  8. Going too rich will reverse the revving effect of the choke and start to make the engine slow down.

    I'd say you bike is running too rich on the idle screw and/or idle jet and the extra choke at this time of year is too much.

    Clean the carbies, set the float height, sync and then set the idle jet screw properly.
  9. +1 to what ibast said. My bike is the same. Choke only really works when its cold cause the air is denser but if I lean it out it runs too lean and hangs if I blip the throttle. ;)

    EDIT: Mind you. when weather is normal, i dont need to use the choke at all.
  10. It is typical of Hondas
  11. Thanks guys, I'll experiment with it and I'll hopefully get a positive result.