Chad,
First I'd remove the air valve and insure the needles were installed
properly and that as a datum point, the brass portion of the needle is
flush with the bottom of the air valve. Make sure the mating surfaces of
the air valve, diaphragm retaining ring and top cover assembly are clean
and that the diaphragm fits properly in the groves of the air valve and top
cover to insure an air tight seal. Check that the fast idle cam is fully
home. Make sure there is oil in the dashpots. Check that all the vacuum
fittings are tight or plugged and that all the carb mounting bolts are
tight. Be sure to check the banjo fitting on the intake balance bar and
that the brake servo hose is a tight fit at both ends If all is well
there, remember to loosen the coupling assembly when balancing the carbs so
that one can be adjusted independent of the other. Using the Unisyn, rubber
tube or whatever method, insure equal amounts of air are are entering each
carb and then tighten the coupling bolts. Remove the vacuum tube at the
distributor and make sure there is a good vacuum from the hose. When you
remove the hose there should be an increase in RPM's if the vacuum retard
is functioning properly. Assuming the timing and dwell are close to where
they should be, you should be able to get a 900RPM idle. If not, you might
want to pull the carbs and go through them to be sure your friend didn't
mess something up internally during his rebuild.
Hope this helps,
Jim Davis
Fortson, GA
CF38690UO
CF37325U
Chad Stretz wrote:
> The thread on Unisyns lead me to this:
>
> Last night my friend brought his 71 TR6 over for a carb adjustment. He
> had just replaced his needles, and re-adjusted his floats. For some
> reason, I had to back out the idle adjustment screw on the rear carb
> all the way to keep the engine from racing. When I backed out the
> front carb screw to try to balance them the engine stalled.
>
> The beast misfired horribly, and lifting the air pistons on both carbs
> revealed a lean mixture. No amount of adjustment would cure this
> completely. The chokes were closed as far as I knew.
>
> ISTR the throttle shafts being in pretty good condition, so I don't
> think they were a factor here. (I'll gladly check them again if I need
> to.)
>
> Before I started messing with the carbs, I checked the timing. I went
> from about 9 degrees BTDC to 4 degrees ATDC with no appreciable
> difference. The vacuum retard is connected.
>
> Am I missing something obvious here? I've read the article on carb
> adjustment in the VTR maintanence pages, but if anyone would like to
> comment I'd really appreciate it!
>
> I'm starting to suspect the bypass valves simply because I don't fully
> understand what they do! Temperature compensators?
>
> In the corner wearing a dunce cap,
>
> Chad Stretz
> 73 TR6
> CF7511U that except for poor gas mileage, runs fine after the same
> adjustment!
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