The CRF250L Owners thread

Discussion in 'Thumpers' started by joec63, Sep 4, 2012.

  1. NJ-Brett

    NJ-Brett Brett

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    I think a camshaft position sensor would be a first on a bike, A Japanese bike anyway...
  2. Spud Rider

    Spud Rider Long timer

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    That's great, Guru! Please do start a new thread, either here, or at Thumpertalk! :y0!

    I believe the ECU is part #16 in the following diagram.

    [​IMG]

    This unit only costs $73. :D Would it help your diagnosis if we chipped in and bought you an ECU? :deal

    Spud :beer
  3. Ed@Ford

    Ed@Ford Long timer

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    Yes, you are exactly correct...this experiment is simply an experiment to see if the engine is going lean, or low on air & fuel and is momentarily "strangled" due to that lack of air. With your background...which probably included the trials and tribulations of emissionizing automotive carburetors, you are probably well aware of why they all had "dashpots" to allow the throttle to close the last little bit slowly and uniformly. The experiment will give us a clue of a cause for the stalls....but more than likely, this would not be the "proper" fix.
  4. Ed@Ford

    Ed@Ford Long timer

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    SPUD: You bring up another issue pointing out that the engine computer is only $73. I seem to recall reading a rumor that there were "race" versions of the computer that could be used on the CBR250R "street bike" that made much more than the 25 horse the CBR was rated at....does anyone else remember such rumors?
  5. Ed@Ford

    Ed@Ford Long timer

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    Putting a cam sensor on a single cylinder 4 stroke is unnecessary. It's extremely common to have a spark on BOTH upstrokes of the piston...one lights the mixture on the compression stroke, and the other just sparks on the exhaust stroke....the common description for this is "throw-away-spark".....so don't bother to look for a CMP on this engine

    One thing I WOULD like to understand is how the second exhaust gas oxygen sensor is used on this engine....RamZ describes it in Honda literature....but I still don't understand the "whys".....and it better be a good explanation...oxygen sensors are not inexpensive....their value is in $$ not cents.
  6. 'Flagger

    'Flagger ..this space for rent..

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    Using the abbreviations shown in the service manual:

    MAP Sensor
    TP Sensor
    ECT Sensor
    O2 Sensor
    IACV
    CKP Sensor

    No Camshaft Sensor
    Also has an IAT Sensor
    Don't see a Barometric sensor
  7. Spud Rider

    Spud Rider Long timer

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    A quick google search yielded the following information, Ed.

    http://www.cbr250.net/forum/cbr250-performance/3328-hrc-cbr-has-map-adjustable-ecu.html

    http://www.jetsetracing.com/ecu cdi/cbr250r/cbr-250-250r-ecu.html

    <iframe width="640" height="360" src="http://www.youtube.com/embed/sxOmKNIWuyU?feature=player_detailpage" frameborder="0" allowfullscreen></iframe>

    Apparently the race ECU is very expensive. :huh

    Spud :wave
  8. 'Flagger

    'Flagger ..this space for rent..

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    Service manual shows only a single O2 sensor, up near the exhaust outlet from the head.
  9. Spud Rider

    Spud Rider Long timer

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    Part #11 in the following diagram is an oxygen sensor; it costs $55. Is there another oxygen sensor on the bike, Ed?

    [​IMG]

    Spud :beer
  10. 'Flagger

    'Flagger ..this space for rent..

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    See my previous post.
  11. Spud Rider

    Spud Rider Long timer

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    You beat me by 5 minutes, 'Flagger! :lol3 I was composing my post while you were placing yours. :wink:

    Spud :beer
  12. 'Flagger

    'Flagger ..this space for rent..

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    No worries ... I was searching for this mystery race ECU at the same time as you ... found the same CBR25R.net article as you did ... even went to HRC's site to find some more info and didn't get very far.
  13. toddol1971

    toddol1971 Adventurer

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    if I was on anything smaller than a big scooter over here I'd be more than nervous. Luckily where I live its way out in the country. To many people on phones, texting or whatever they do. My mom just called me this morning and told me that she had been hit by a jeep. Guess what the lady in the jeep was doing?????? Stupid, stupid people. Then she tells my mom that this is the 4th time this has happened to her, like it was my moms fault. I'm telling ya its like every 50th person had a lobotomy over here. I'm sure its everywhere though. It seems like its mostly kids to me age 16 to 25 ish. Keep your eyes open for the meandering wasps over there.
  14. Krono

    Krono Perfect Liner

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    This sounds a good idea to me, since this one is mostly about racks and bars.
    It could be a "tech-tread" about engine, from intake to exhaust, electrical, and so on ..

    L
  15. SAPB

    SAPB Long timer

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    I can't remember if it was on this thread or I read it someplace else. Might have been Bake posting about Bill Blue's CRFL strip, and punching out to 280? This is a ground up new engine, but I wouldn't be surprised to find that all these sensors are interchangeable within the Honda family, maybe even to the cars. Usually, when this happens, they have looked at the future emissions, and are already there now. All that "stuff" on our CRF is to make it compliant, probably not only here, but for worst case scenario, world wide. One exception was the Thailand guy saying that his muffler didn't come apart like ours, to get to the spark arrest screen, but for the most part, this is the same bike everywhere. Looked for the Ramz post about how this bike can "talk" to a computer, but couldn't find it. He did reference how the DLC plugs into the UDS pocket tester, back on page 19, post #266. Unfortunately, a UDS is not in my tool kit. Anybody got a WCD (Weather Changer Device)?
  16. mtntrails

    mtntrails Life is Short...

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    :lol3
  17. SAPB

    SAPB Long timer

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    Oops, page 18, HDS. Looks like you can get one from Helm, $2704, in stock!
  18. NJ-Brett

    NJ-Brett Brett

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    The MAP Manafold Absolute Pressure would be the same as a barometric sensor, no?
    And I think all FI bikes have an intake air temp sensor.

    As far as two oxy sensors go, cars use the 2nd one (post cat) to measure that the cat is working, a requirement on cars....

    Is Honda getting the systems like cars?
    In some ways it would be great, as those are wide band systems, from idle to full throttle, unlike the 'just where the EPA measures' systems on most bikes.,
    My TU only looks at the oxy sensor under mid throttle and mid rpm's, it does not look at it at idle, at full throttle, , or low or high rpm's, and my bike does not spend a lot of time in the oxy sensor zone!

    A wideband system would allow changes without needing to program anything, like cars, the system would just adjust for any changes, but with a 2nd oxy sensor, you could not remove the cat or change the exhaust without setting a code.




  19. MentalGuru

    MentalGuru Crazy Diamond

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    Thanks :beer

    I'm used to using the standardized automotive abbreviations. :D So keep that in mind.

    They must be using the MAP sensor to read Barometric pressure at key on then. This would be how the PCM checks altitude.

    I figured it would have the IAT sensor = Intake Air Temperature sensor. Thanks. :thumb

    I have a link to the Honda parts catalog which is one of the things I needed.

    What I would really like to see is the wiring diagram. :deal Pictures are always nice too, I have a few collected. :wink:

    The lack of the cam sensor and 1 wire narrow band O2 sensor shows me it is a early basically an early type automotive system. That means the PCM is most likly a PROM type instead of a EEPROM type. :1drink

    This type of system doesn't do to much OBD so it is easier to trick it as needed. This also makes diagnoising and testing easier for the average backyard tech. :nod

    :kumbaya
  20. MentalGuru

    MentalGuru Crazy Diamond

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    You should... It's your motorcycle, just ride it to where the weather is nice. :lol3


    :freaky