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How To: Kickstarter pin

April 3, 2010

Burman1926_01 Burman gearboxes were used by Ariel, Vincent, AJS, Matchless, Panther and other manufacturers from the 1920’s through the 60’s.  They were decent boxes, and took the power of a Red Hunter, Square Four, early Vinnie twin, 7R, etc.  My only complaint of them is that the early ones tend to be a bit tough to nick into gear without a strong boot and a resulting ‘clunk’ noise (much like a /2 or /5 BMW).  Double clutching is required for smooth shift, especially when shifting down.

The early models did not have a folding kicker pin (the part with the rubber that fits into your boot heel), so it stuck out sideways even when it wasn’t being used to start the bike.  It was threaded onto the kicker arm, but tended to come loose due to vibrations.  If it didn’t unscrew itself and fall off into a ditch, the kickstart after the next stop would typically bugger up the threads…  Hence there is now a market for replacement kicker pins. The part on Kim’s Ariel was die-cast, with a parting line running across the threads in two places.  It never screwed in tightly, and wasn’t going to stay in place.  So we quickly made up a new one:

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A simple bit of turning work, starting with about $5 worth of 12L14 bar from McMaster Carr.  This is mild steel with Lead added to make it easier to cut;  The lead lubricates the surface as the tool cuts into the steel.

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In this view, the threads will be on the right, the rubber will fit on the left.  The live center is the tapered part that is supporting the right end of the workpiece.  I was able to do the whole part in one setup, which keeps the various surfaces of the finished part all concentric to each other.  (that is overkill for a simple kicker, but it is good practice).

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1.  Raw material.  2.  Finished Part.  3.  Bad die-cast reproduction part.

After the lathe work, a quick session on the mill cut the two flats which are required for the wrench during installation.

You’ll see that I made the threads longer than the original.

 

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Those longer threads were used to install a nut on the backside of the kicker arm.  This nut now locks the threads of the pin against the threads in the kicker arm, so the pin cannot come loose due to vibrations.  Jam nuts (aka double nuts) are a great way to keep threaded joints tight in many places in bikes and other machinery.  Try it on your rear brake rod.

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for kim 001A happy wife at the Legends Show a few years ago.

 

 

 

Want to fit a Burman 4 speed into your 3 speed Indian Sport Scout or 741?  look here.

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3 Comments leave one →
  1. Richard McKenney permalink
    April 4, 2010 5:22 pm

    Brilliant Site, more please, a real hands on Presentation,wonderful!

    Any idea how to put teeth back on to a kickstart quadrant in a 3 speed Burman Q box ?

    Occhio Lungo? You must be an an optometrist?

    Keep it up, great job.

    Richard

    • Pete Young permalink*
      April 4, 2010 8:00 pm

      Hi Richard. Thank you for the feedback!

      Literally translated from Italian, Occhiolungo means “long eye”. But loosely translated it means something like: “a guy who can see a bit of the future and who might pull a trick on you” !

      I haven’t tried replacing the teeth trick on a kicker quadrant, but the tough part would be finding the center of the pitch circle on the old teeth. It could be done with some good indicator work on a mill I think, with some math. Once you find that, you can create a jig to hold the quadrant and the new teeth into place. Did the Q share the same quadrant part number with the BA or other Burman boxes? BA bits aren’t too tough to find.

      cheers mate,
      Pete

  2. Richard McKenney permalink
    April 12, 2010 3:55 am

    G’day Pete

    Soooo! your a tricky guy ay?

    Not sure about the BA box sharing the same parts with the Q box?
    I have other Burman quadrants and ” Missed it by that much”, (Get Smart) you know.
    I’ll probably have to make one, eventually.

    I’m battling with my 1914 Triumph I killed, seized it solid after a four year resto so it’s back to the beginning.

    Your site is “Brilliant” it looks like you’ve been to Nirvana and back ( no not the Band) a few times.

    It’s food for plodders, like myself, working in isolated country towns in Australia.

    Cheers Richard

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