Listers!
Many thanks to the ones contributing (Aaron, Dick Taylor, and Hugh
particularly on the High Idle Thread from early 2003) and the 6-Pack management
for
maintaining the email archives. I have finally fixed the high idle problem I
was
having. Did all the cylinder compression tests, set timing, dizzy springs,
greased the dizzy weights, tuned temperature compensators, fiddled with mixure
and
colortune, blanked off choke feed, adjusted carb floats, adjusted the
needles...to no avail. Then I spent several hours searching the archives.
Turned out to be the bypass valves floating. I completely blanked the bypass
off with gasket material and the idle and engine braking was good...presto!
Since there is a slight bypass always happeing due to the design of the valve I
did not want to leave it completely blanked off. So I decided to adjust it.
Mine are supposed to "not" be adjustable so I figured they were fine when I
replaced the diaphrams. This was not the case, but once you get them apart the
inner spring keeper threaded to the screw can be pulled out of the outer body
of the bypass with pliers. I decided not to break out the brass plug at the
end in fear of adding additional vacuum leaks. Instead, I adjusted the spring
keeper all the way towards the carb body to leave the hexagonal spring keeper
lip just inside the bore slot. This unfortuneately did not solve my problem as
bypass valves still floated when engine rpms rev'ed above 1500rpm...but not as
bad as before. Since I made the maximum adjustment to tighen up the spring I
checked catalogs for new springs and did not find anything but completely new
units for around $85 each.
I decided to fashion a spacer to add like a shim to the inner spring keeper
to tighten up the spring tension a bit more. I added about 0.1" of a stainless
steel tube and now the brass disc just barely comes off its seat with finger
pressure. Essentially the only bypass I am getting is through the slot cut out
in the gasket material for the two larger holes. Reinstalled them and she
idles about 700-750rpm very smooth. Timing set at 4ATDC with new vacuum retard
and
with vacuum retard disconnected timing swings to about 10-12BTDC which is
normal. Short test drives and I have no popping under engine deceleration and
idle comes back down well when you take your foot off the pedal.
Now it is off to air balancing the carbs and tweeking the mixture needles a
bit. Just wanted to share a success story from the archive info. Thanks again.
Michael Rankin
1971 TR6 CC 61212 L
Louisiana, USA
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