power loss on acceleration

Discussion in 'Maintenance' started by PaddyJo, May 22, 2018.

  1. PaddyJo

    PaddyJo Active Member

    Joined:
    Apr 30, 2015
    Messages:
    6
    Likes Received:
    3
    Hi all,

    I need some guidance. I have a CBR1000RR 2005 which I do not thrash. I had an issue yesterday when accelerating in gear to pass some cars when the bike made a "whaaaaaaaaaaa!" sound, but no obvious or surge in rpms on clock, and lost some power. When I rolled back off the throttle to 3000 to 5000 rpm it continued. I rode it cautiously home. The only thing I did in the time frame was make a small adjustment to the idling speed using the twiddler as seemed to be running slightly higher revs when stationary, but put it back afterwards. Spoke to the garage and they had no clues but could take it to them for checking.
    Hoping it is not loss of compression (Please no!) , fuel pump (Fowlers £666!!! FFS), has had a major 22k service last year and new sparkers, has K&N air filters within last 18 months, and change of oil and coolant, Stator and reg/rec also replaced with after market.

    Ideas? Diagnostic directions?

    Paddy
     
  2. PaddyJo

    PaddyJo Active Member

    Joined:
    Apr 30, 2015
    Messages:
    6
    Likes Received:
    3
    Ok, after a test run the issue is that after about 8000rpm the power delivery stutters. Sometimes it clears and pulls straight through 10000rpm and sometimes not so well. So I am thinking that it is crappy fuel, blocked fuel filter, or that the after market delkavic pipe was not tuned properly. Air filters I replaced with K&N about 18 months ago and the sparkers were changed last service. Any other ideas?
     
  3. blake7

    blake7 Active Member

    Joined:
    Feb 16, 2011
    Messages:
    685
    Likes Received:
    158
    Faulty tps sensor maybe? Can be tested with a multimeter. Sometimes kinked pipes under tank can give the same issue but if yiu have not had the tank up/off recently then that can be ruled out.
     
  4. PaddyJo

    PaddyJo Active Member

    Joined:
    Apr 30, 2015
    Messages:
    6
    Likes Received:
    3
    Reading up about tps power loss should come from acceleration start but as this is mid to high I am thinking it isn't but will check anyway. I have had my mechanics check the bike on a dyno and they are leaning in the direction of the fuel pump being the possible cause. At £499 for a like for like from Fowlers it will expensive if that is not the final diagnosis.. ...
     
  5. nigelrb

    nigelrb Elite Member

    Joined:
    Nov 2, 2017
    Messages:
    9,804
    Likes Received:
    3,371
    I've had Delkevic before and know others who have. Good units. Fairly sure you could rule that out, but more than likely the dyno boys have already told you that. I actually thought the dyno would provide a definitive answer, given that fuelling is a major component of dyno results . . .:confused:
     
  6. PaddyJo

    PaddyJo Active Member

    Joined:
    Apr 30, 2015
    Messages:
    6
    Likes Received:
    3
    Thanks Nigel. They are running it on the dyno again tomorrow with another mechanic for a 2nd opinion. They did confirm that it does run dangerously lean on anything other than mild acceleration above 6000rpm and when it does happen backing off the throttle brings the power back. Haven't checked the electrics to the pump to see if that is not providing enough power for higher flow rates but will need to find a check for that. I have checked foe cheaper alternatives to the Fowler pump and seen cheap pump motor replacements. Anyone have any experience of these?
     
  7. callumw

    callumw Active Member

    Joined:
    Aug 19, 2012
    Messages:
    765
    Likes Received:
    249
    Check the cables to the second bank of injectors (and check the injectors themselves)?

    AFAIK, the second set of injectors are activated at 8,000 RPM and if that's where you're getting the issue then that's likely the cause.
    Intermittent may just be a bad connection.
    Alternatively could be fuel starvation when the other injectors start asking for fuel (so, fuel pump and fuel filter).
    Worth checking the second injectors first tho. Could be an easy fix :)
     
    • Agree Agree x 1
  8. PaddyJo

    PaddyJo Active Member

    Joined:
    Apr 30, 2015
    Messages:
    6
    Likes Received:
    3
    Hi Callum

    So the 2nd mechanic didn't need a dyno run and ran a diagnostic tool on it that showed cylinder 2 had a duff injector so he took it out, cleaned it and put it back and we are all good again. Looks like you were spot on! I did buy a new, but Chinese fuel pump and 2nd hand injector rail with injectors just in case which I will get ultrasonic cleaner then fit. Thanks all!!
     
    • Like Like x 3

Share This Page