Thanks to all the helpful hints that I received regarding the high idle
problem that I was having with my dual Z-S carbed 1980 TR7. Just to remind
everyone, the problem was that I "rather suddenly" developed a fast idle
(about 1200 r.p.m.) about two weeks after I rebuilt both of the carbs. Most
of the responses suggested that the vaccuum advance/retard unit was probably
toast and I felt that this was probably a pretty good guess. I finally had
a chance to thoroughly check everything out this past weekend (while I was
replacing the rear shocks, naturally) and I was somewhat suprised with the
results. The timing was spot on, the vaccuum unit seemed to be working (the
RPM's went up about 100 revs when I disconnected the vaccuum hose) and all
the mounting bolts on both of the carbs were tight. Hmmmmm. Anyway, after
much head scratching, I decided to go right back to the most basic setup so
I backed the adjustment screw that rides on the choke cam right off and
the idle magically returned to 800 RPM's.
It turns out that I must not have tightened the nut down that secures
this adjustment screw and during the normal operation of the car the screw
had vibrated down out of position such that it caused the throttle to be
partially open all the time. It was a particularly tricky little problem
since this screw normally rides fairly close to the choke cam anyway.
So, the moral of the story is : Tighten your nuts or you might get
screwed... Well, maybe that's not much of a moral but I hope my
absentmindedness prevents someone else from experiencing the same
difficulties.
Cheers
David
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David Crouch o
School of Kinesiology /~>
Simon Fraser University o......./<
Burnaby, B.C., V5A 1S6
Phone (604) 291-5770 E-mail davidalc@sfu.ca
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