[TR] mild cam update

[Randall]

> bolts on with 2 bolts but 4 holes.........two are 
> offset.  would this make any differance?  

Well, yes.  Those holes (in addition to being able to flip the sprocket
front/back) allow for adjustment of the cam timing in roughly 4 degree
steps.  Camshaft timing is just as important to engine performance as
ignition timing, even though it's not as easily adjustable, so IMO the cam
timing should be checked any time you disturb it (for example by replacing
the camshaft).

-- Randall