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Help Honda CBF250, ran, leaked and now won’t crank?

Discussion in 'Honda 250cc Singles' started by hogclassics, Sep 26, 2023.

  1. hogclassics

    hogclassics Active Member Premium Member

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    My Bike:
    Honda Super Magna (x2) , V30, Goldwing (x2) CBF250 2008
    Hi riders & wrenchers.

    I bought a little Honda CBF250 06 dead on EBay.
    This is for a bike for any friends who wanted a family ride out.
    Slim enough not to fill the 5 bike garage.

    Greetings from across The Pond!

    On checking the compression, it was 50 psi and it needed a new top end build,
    a compression test now shows 160 psi.
    The charging was low, stator rewound and replaced.
    The regulator rectifier was upgraded to a Mosfet one.
    New battery - Motobatt 130 CCA.
    New starter motor.
    New starter solenoid - UK made.
    New Honda neutral switch.




    The first ride out/ shake out, 2 weeks ago resulted in the bike crankcase sprung a small leak.
    Dad advised ‘I should’ve changed the used gasket, for a new one, but didn’t
    and never told me!’

    The bikes crankcase was cleaned thoroughly and 3 Bond, as used on motorsport
    vehicle sealed the crankcase well.

    I discovered the previous had also used thin gauge copper cable on the starter solenoid to the battery positive and this got very hot, also the battery got too hot too.

    The solenoid to battery positive cable was upgraded to the correct gauge.
    I changed the battery too.

    On turning the ignition key, all the instrument gauges self checks and all the bike lights work.
    On seeing the neutral switch, side stand down, I pull in the clutch lever and push the start button.
    The bike clicks, once nothing more.

    All fuses. check, all check ok.

    I’ve changed the starter solenoid and removed the new starter motor and tested it, it spins up
    with gusto, lots of power there.
    I’ve now reinstalled the starter motor.
    Connected the battery.

    Just a click, no crank.
    Swopped out another working starter solenoid, same ‘just click!’

    I’ve jumped the clutch, side stand safety switches, all good.
    Also checked cleaned the brass connectors in the start switch
    and it just ‘clicks’.

    Finally swopped out tri diodes and 2 pin diode and that didn’t do anything.

    My final test was a voltage drop test and it went from 13.00v to 6.00v.

    I’m unable to bump start it as I’ve a disability.

    The bike lights up and wont crank, just a ‘click’.

    What a conundrum, the bike ran a fortnight ago, yet no won’t crank, silent.

    Any help and greatly appreciated biker buddies.

    Many thanks

    Hog
     
  2. Brian Walker

    Brian Walker Member Premium Member

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    Maybe take out the plug and see if it spins with low load. Seems like you have done most things, see if you can get someone to give it a bump start in case something wasnt right when you reasembled the cases and its too tight somewhere.
    Good luck, great little bike.
     
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  3. Linkin

    Linkin The Mechanic Premium Member Contributing Member Dirty Wheel Club

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    Voltage drop test is the key there, you have gone from 13v to 6v indicating 7v of drop in the system from the test points. You have a connection issue somewhere in the starting circuit
     
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  4. DannoXYZ

    DannoXYZ Well-Known Member

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    How were you able to do this compression test?
    Was starter able to spin engine then?
    What happened between then and now?

    Where were meter probes touching for this test?

    Remove starter from engine, but leave all cables connected. Use jumper cable to ground mounting ear of starter to -neg terminal of battery. Push START button, does starter spin easily?

    Remove little cover on flywheel case cover and see if you can turn engine by hand with wrench.
     
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    Last edited: Sep 26, 2023
  5. hogclassics

    hogclassics Active Member Premium Member

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    My Bike:
    Honda Super Magna (x2) , V30, Goldwing (x2) CBF250 2008
     
  6. jmw76

    jmw76 Well-Known Member

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    Take all the plugs out and see if it will turn over on the starter.
    If still no good, put it on a rear stand, put the bike in gear (ignition off) and see if you can turn the rear wheel by hand.
     

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