Finally got to Grandfather's tuning this weekend but discovered
a surprise! He's got the smog type carbs -- all one piece (no
seperate float bowl) and the jet assembly is hidden in an
enclosed box below the damper mechanism. Only adjustment is a
mixture screw and the idle setting screw. Of course, Rogers
(and Scotts and others) instructions work equally well counting
turns as castellations.
One thing I'm not sure I've seen mentioned is the choke cam
that lifts the idle screw. It turns out that Grandfather's
primary problems was that the aft carb's linkage had moved
just enough on the shaft so that the idle screw wasn't even
in contact with the cam! This is why Terry had good results
leaving the choke always set just a bit -- it turned out to
be just enough to rotate the cam into contact with the screw.
Of course, he runs smoother with both cams synchronized so
that the amount of lifting is equal on both carbs. So...
before getting out your Uni Syn, take a good look at the
linkage mechanisms for both the choke and throttle and make
sure they are adjusting both carbs equally. If not, there
is an obvious nut to slacken to allow the cam to rotate
on the shaft.
- Dale "SU's suck!"
|