Hi all -
Here's the latest on my SU balancing problems. There was actually more than
one problem and one still exists, but it's not too critical and I will fix
it next. First of all. The jet (#1) that I had thought was maybe not
centered was centered. This is the one that I took apart completely to see
how it all worked. I had a bit of trouble getting it centered when I
re-installed it and I thought it might not be right and hence my problem.
Upon re-checking last night it was properly centered. It was the other one
(#2) that had problems. I originally just checked it without disassembling
but when I started to adjust the mixture on it (#2), unbeknownst to me at
the time, the locking nut was just loose enough to let the jet bearing turn
with it, thus uncentering the jet! And it (#2) had a burr inside the piston
chamber that would bind the piston occasionally (I missed that one
completely the first time around).
So I went through the complete procedure again last night and now I have
balanced carbs with the mixture properly set on both, i.e. they both pass
the lift test. The remaining problem is fast idle speed. I can't get the
idle down lower than ~1200rpm. I think I've got an air leak somewhere and
that will be my next project. I still think, though, that #1 carb is sucking
more air than #2 because its throttle adjust is off the stop when balanced
with #1, so I don't have any more adjustment to lower the idle speed.
Many thanks for all the suggestions. Answers to specific questions are:
I did have the throttle shaft connecting both carbs disconnected.
Both jets are centered.
There are no burrs inside the suction chambers, both pistons move freely and
silently.
Both needles are the same and are not bent.
Both dash pot seat squarely on the carb body.
So the last thing is airflow. I'll check that the throttle plates are
closing completely.
Many thanks to Ken Porter, Bob Howard, David Tinker, and Gene Fodor (are you
any relation to Eugene Fodor, the violinist?).
Lani Spahr TD #5550
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