Featured Contaminator Twin

Discussion in 'Other Bikes' started by speedrattle, Sep 13, 2022.

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  1. speedrattle

    speedrattle Senior Member

    Feb 19, 2021
    735
    243
    appalachia usa
    #1 speedrattle, Sep 13, 2022
    Last edited: Sep 14, 2022
    cant really call it a contaminator after this morning

    [​IMG]

    this 1970 norton has always been a frustrating machine because of the poor clutch engagement. grabby, very much an on-off thing. the gearing on this is sufficiently low that an on-off clutch wants to lift the front wheel, which is distracting. been that way since i bought it.

    i tried adjusting it out, working on technique, so on, so forth. was trying to avoid breaking open the primary to look at the plates. there was some sort of ATF in the chaincase, didn't know what kind, but ATF is a common recommendation. thought and thought.

    so then i said, whatever. this morning i took the vacuum pump with a fluid extraction fitting, popped off the access plugs and sucked all the ATF out of the chaincase. pretty dark, and im still clueless as to what it was. took out the level plug and carefeully poured in a fill of Type F ATF.

    not dexron, not mercon, not universal, just the ancient Type F that they used to recommend back when there were still vehicles that used Type F, which is certainly not anytime recenty. then i took it to town.

    the clutch was transformed. i'm used to changing out modern SN motor oils in triumph wet clutches because it makes them slip, but it always takes a while for the correct oil to re-saturate the plates and start to work correctly. changing to fresh Type F oil in the contaminator showed an improvement before i got out to the road.

    smooth engagement, predictable, consistent. like night and day from the wheelie-or-stall situation i had before.

    so i rode around in the autumn morning, then came back to the shop and parked it. still some issues to work through. it had been most of a year since i took this machine out because it was always so unpleasant to ride. the shorai battery still starts it first or second kick, even after sitting a year, but the too-short kickstart lever is still a pain, as are the stock inaccessible side and center stands . . . i can start accumulating stuff now to fix those.

    but now i have to think of something else to call it.
     
    • Like Like x 7
  2. darkman

    darkman Crème de la Crème

    Oct 26, 2015
    7,058
    1,000
    Southcoast of the UK Earth
    Great news on getting yer finger out and sorting it, great looking early commando :)
     
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  3. speedrattle

    speedrattle Senior Member

    Feb 19, 2021
    735
    243
    appalachia usa
    #3 speedrattle, Sep 16, 2022
    Last edited: Sep 16, 2022
    it was a chopper rescue, years ago. looked like this before i got it

    [​IMG]

    [​IMG]

    the guy before me found all the missing bits, put on a boyer and a podtronics, new amal concentrics, located a NOS sidecover in new zealand to copy the original fireflake roman purple or what ever it is from. then he got tired of not having turnkey japanese mechanicals and sold it to me.

    the clutch was all that was wrong. it handles somewhat better than my daily triumph, although its much slower. the one-up three-down shifting feels natural after a mile or so. i havent had to do anything except locate original side and center stands, and a front mudguard stay. i experimented with the jetting but its spot on. even the isolastics work as they should, and it doesnt vibrate hardly at all.

    a very nice machine. really, the only things it needs are a fork lock cylinder and a longer competition kickstart lever from andover. the stock lever is too short, and kickstarting is a pain. but that piece is 200 quid, so it will wait.

    besides, i have another machine that needs attention before the weather turns

    [​IMG]
     
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  4. darkman

    darkman Crème de la Crème

    Oct 26, 2015
    7,058
    1,000
    Southcoast of the UK Earth
    Great job on the rescue of the Commando :) BSA looks tidy as well.
     
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  5. ian650

    ian650 Well-Known Member

    Dec 6, 2017
    130
    93
    Telford
    "but now i have to think of something else to call it."

    Decontaminated twin?
     
    • Funny Funny x 2
  6. speedrattle

    speedrattle Senior Member

    Feb 19, 2021
    735
    243
    appalachia usa
    i cant take credit for the commando. the PO did most of it, and i am the beneficiary.

    the victor is a leg breaker. i still cannot start it reliably
     
  7. speedrattle

    speedrattle Senior Member

    Feb 19, 2021
    735
    243
    appalachia usa
    its a great motorcycle. handles well and consistently. still tries to lift the front wheel. ive never counted the gearbox sprocket teeth. it might benefit from a higher gearing.
     
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