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cbr loss of power

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by trav111, Apr 4, 2005.

  1. hey dudes
    im having a problem with my cbr250rr (MC22) which i bought about a month ago.... she loses a load of power, more noticably lower in the revs (<8000) but across the board to a lesser extent. basically it feel like i am running out of fuel even when i have a full tank.
    the wierd thing is, i have never been able to run the tank to anywhere near empty, there is always a few litres in when i fill up (i use mobil 8000 usually) and filling up sometimes rectifies the said problem. also wierdly, the problem seems to occur less at the beginning of a ride than at the end. :?
    i have tried the cup of metho in the tank fix, but to no avail. also, i just got my bike back from a major service (which really pisses me off) so all the filters are new etc...
    so i will be taking it up w the shop that did the service, but thought i would try and tap the wealth of knowledge here first... i reckon its gotta be something in the tank or fuel system somewhere, does anyone have any suggestions on what it could be and how to fix it?
    thanks for the advice and awesome site

  2. unfortunately, i doubt the major service would have touched on the fuel system unless you told them about the problem and asked them to fix it. first thing i'd do is give the carbs a clean using one of those sprays (not the fuel additives). its fixed up my cars before and helped my GFs XJR and it only costs a few bucks so its worth a try.

    are you blowing any smoke? if so, what colour is it? your choke may be stuck on or air filter may be blocked up a little (THEN you get nasty with the service joint). could possibly be a problem with the fuel feeding to the carbs but i'd think you would just be stalling instead of running badly.

    i'd start by pulling the tank off and giving the carbs a clean. while your down there, check the choke is opening and closing properly. and if it still runs like a bag of crapola, ask someone that knows a bit more than me cos thats about all i can come up with :LOL:
  3. Daniel IMO sound to me like you have a blockage in the fuel system. As you said filling up sometimes fixes the problem, and with a gravity feed system more fuel in the tank causes more pressure which allows the fuel to force its way past the blockage. What I would check is the fuel line from the tank to the carbie to be sure that there is no constriction be that a twist, kink or a miss placed spring clip.
  4. Sounds to me like gunk in the tank when it runs low, which iunterferes with the fuel flow when the fuel levels are low in the tank.
    It could be something simple like a blocked fuel petcock which feeds the fuel from the tank to the carbies.
    If possible remove the fuel tank and give it a good clean.
  5. ill have a poke around with those things in the next couple o days.
    many thanks dudes :)