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Shovel spark plugs

  • sled56
    sled56
    13 years ago

    I removed the plugs from my 77 FLH, they are harley 5RL, clymer manual says these are for 80 and up shovel, should be 5A6. OK the NGK equivelant is aprox. 8mm shorter in the reach? Any info appreciated.   

  • sled56
    sled56
    13 years ago

    Bike ran fine when warm, idled fine, plugs were black and a little sooty but typical of unleaded. Checked the chart and the NGK,s I bought are shorter than the 5RL,s. Torch down the head tells me that the long reach plugs were ok, no high top pistons etc. so given your experience should I stay with the 3/4 length or fit the shorter NGK,s??

  • sled56
    sled56
    13 years ago

    Thanks for the words of wisdom.

    Cheers

  • daddyracer56
    daddyracer56
    13 years ago

     1977 to 1979 was the new then long reach plug 3/4" long thread  lenght or 19 m.m.  pre 1977 to 1979 was short reach 3/8"  lenght  thread 9.5 m.m.  measure the thread lenght in the head  where the spark plug's  go ,    because in between years there , do not put a long plug in a short hole

  • sled56
    sled56
    13 years ago

    Thanks for the input  , found that NGK BPR5EY is the correct one for my setup, thread length is correct and the electrode length is a fraction shorter than Harley 5RL.

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