TR6 choke cable

[Ian Macky <imacky@us.oracle.com>]

I got several interesting mails about choke cables.  Arthur Freeman and
Mark Banaszak-Holl talk about D-shaped grooves and washers and cabbages
and things.  I *think* I know what they're talking about.

There *is* is a groove on the shaft the knob connects to.  Perhaps the
friction mechanism is worn out, or the washer is missing or something.

I guess I'll pull this again and take a closer look.  Hmmmm.....

--ian