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zzr250 wont rev hard

Discussion in 'Technical and Troubleshooting Torque' started by Doch, Mar 10, 2007.

  1. G'Day I was sitting on about 110 @ about 9k rpm when 20 odd k's before due the engine started to run as if it was running out of fuel, spluttering and surging, i switched to reserve, stopped and refueled but the problem has persisted.

    I've dissconected the fuel line and filter and blown it through (very hard to do so and I'm not even sure if I was successful) but still it takes about 3 days for the engine to respond to the throttle as if its running on full choke.

    Because I dont use the choke I checked to make sure that it hadnt stuck but all I found was that the cable was broken at the lever end.
    I've also removed the air filter and started the engine. no diffrence

    Any ideas on what it might be

  2. There may be a number of issues.

    First one is your breather line. When air doesnt get into your fuel tank, it prevents the fuel from being fed into your fuel lines (and fuel filter). Remember that old 'fingertip over the straw' trick? Well its a similar concept. You can check if your breather line is blocked by opening up your fuel cap next time your bike does this. If you hear a 'gush' of air going into the fuel tank, you know your breather line is blocked.

    Some other issues could be: spark plugs are fouled or dirty. Or your main jets are clogged up.
  3. if the choke lever is broken are you sure it's not stuck on down in the carbies?