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ZXR 250/ZX2R non-responsive throttle

Discussion in 'Technical and Troubleshooting Torque' started by Benlui, Sep 27, 2011.

  1. Hi guys, second time I'm asking for help here, and this place seems to be a great community so I thought I'd try again.

    My bike is one of the high reving inline4 250's and I hadn't given it a good ride at speed since I got it till now... so I'm having a little trouble pinpointing where/when the issue started... But I went for a ride last night, started the bike, let it warm up for about 5 minutes... and then went off.

    As I went to accelerate I noticed that with each gear I went up the bike felt like it had a lot less power then it should, and the revs refused to go much past about 10 thousand rpm... it seemed to be less willing to go to higher rpm's the higher up I went in the gear range. And what seemed even more interesting, is that it wouldn't even go higher up in the RPM's in higher gears when I held down the clutch and gave it a good rev... I also noticed that when I opened the throttle past a certain point, especially in the higher gears, that the engine was less responsive and almost sounded like it was chocking or spluttering vs when I had the throttle less open.

    now I'm sure someone with more experience then me could come up pretty quick with some potential starting points as to what might be wrong. The only starting point that I could come up with is that I know when it went through road worthy they put some weird baffle thing in the muffler part of the exhaust coz it was a bit loud... I'm wondering if this could be effecting it? but why would it effect it differently at different gears?

    I'd also like to point out that I could literally barely get the bike to go past about 60-70kmh and most cars were out accelerating me easily.

    Thanks in advance for any help, and sorry if this is some really simple problem.
  2. Too much back pressure could certainly cause this. (caused by a baffle in the exhaust)
  3. Yeah, I should have updated this, sorry, I took out the baffle, (which was very strait forward) and the opening in the the centre of it was smaller then a 5c piece. Soon as it was out, was like night and day.

    But thanks for the reply, I spoke to someone else with the same bike who told me how responsive his was... and that's how I remembered it when I test rode it before the road worthy. So I thought I'd start a process of elimination starting with the easiest thing to check... which happened to work.