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fzr400 3en1 with strange problem

Discussion in 'Technical and Troubleshooting Torque' started by buzzawak, Apr 14, 2009.

  1. Hi all. I have fzr400 3en1 which I recently purchased off ebay (have had it 3 days now) with a strange problem.

    The bike starts but it wont rev past idle and needs to be at 1/3 throttle to keep it idling.
    Shut it down and restart a few time (about 4 or 5) then it revsup and act normal. Go for a ride around the block a few time
    with no problem. Jump on the bike again a few hours later and the problem returns.

    I have removed, cleaned and reinstalled exup valve (adjusted)
    Pulled out the carbies stripped down and cleaned.

    Reinstalled the carbies and the bike fired up first go and idles much better and reves.
    Went for a test around the block and the second time around it bogs and dies.
    Once again the same problem (wont rev past idle and I have to have it at about 1/3 throttle to keep it going).
    Try restarting it two time and then it revs up and goes well for like 400 yards, then dies again.

    Managed to get back to the garage. shut her down and restart and all is normal again.

    All suggestion are welcome.

    Thank you
  2. How are the spark plugs?
  3. My fzr250 does the exact same thing on occasions, especially when cold. I have been too lazy to get to the root of the problem, but it seems like its flooding. Keeping your thumb on the starter for a few seconds seems to get rid of the excess fuel and it immediately starts normally.

    Reading fzr250.com, the problem may be float levels, or even a valve clearance issue.

    Keep us informed if you work it out.
  4. What fuel are you using? MY FZR250 did the same thing when I tried PULP. It was very hard to start and would bog right down at low revs you would have thought there was something really wrong. Changed back to 91 Unleaded and problem was fixed.
  5. Dont know, the bike came with a near full tank. But if it was the fuel would the problem be constant and not intermittent ?
  6. Hi Say_wot the bike does have any problem starting so I cant keep my finger on the starter or it will over run it. IT just intermittently does not rev up
  7. Hi geeth, dont know will pull them out tomorrow and have a look. Do you think the plugs are getting fowled ?
  8. fuel, air and oil filters ??
  9. It was only noticeably at very low revs as it would bog down and not spin up well. Like it was flooding and too rich. Is it blowing much black smoke?
  10. higher octane fuel can cause oddness in smaller engines.. if it says use 91... use 91.. damn site cheaper also. 98 will make it harder to start but should run fine after that.. sounds like a fuel delivery issue.
  11. Hi guys,
    I think I have diagnosed the problem. Have spend the last two days.
    Putting back the original petrol tank (had the to remade the front support and fabricating the piece that was chopped of the sub frame.
    So now I have the original tank and seats on. Anyway took it for a spin and the problem reoccurred. So I turned off the fuel and as the level dropped on the carbies it's revs returned then of course ran out of petrol. So it looks like its getting flooded. Tomorrow is the last day of my holidays, back to work on Monday. Hopefully I will have time tomorrow to pull out the carbies and have a look.

    Its very hard (not many were imported to Australia) and expensive to get parts for the 400. Is there a list on alternative replacement parts from other Yamaha models that fit the 400 ?

    Thanks again guys for the help