On 4 Jun 2000, Keith Gernert asked---
>Is there anything I can do to get the carb tuned reasonable close to
>where it should
>be?
The following worked for me on my 79B and was verified by passing
California
smogcheck II. I read about this technique whilst reading up on Fuel
injection tuning and have used it with carb engines too. The idea is
to hook up a propane cylinder to the intake. If the engine is running
rich, adding a little propane will do nothing or make it bog down. In
this case you would adjust the carb leaner. If, on the other hand the
engine is running lean, adding a little propane will cause an increase
in RPM. Adjust to enrich. The point of all this is to repeat this
process until you find that point of adjustment where you get an ever
so slight increase in RPM with the addition of propane and a further
setting to enrich nullifies this effect. The setting obtained this
way will be on the lean side of perfect F/A ratio(sciziometric sp??).
This setting succeeded in getting me passed the smog check. For normal
driving, I would go to the point just rich of this.
This process will not give you the % of CO but it will get you
to
scizio and you may already have the equipment in your garage. You will
need the special carb adjustment tool and a propane torch with the
burner head and jet removed . A vinyl tube is attached in its place.
This leaves the valve on the propane
bottle (I don't know if the trigger type will work) The other end of
the vinyl tube is attached to the breather port in the Z-S carb. This
admits the gas just before the throttle valve. It only takes a small
amount of gas valve opening to get a reading.
A warning is in order here, none of this should be attempted
until
you are sure all other systems are up to snuff. A complete tune up
with new filters, ignition timing, valve adjustment, and engine at
operating temperature are a must. Especially the auto choke system
must be functional, a maladjusted or leaking choke will cause a rich
condition that no amount of needle adjustment can fix. A cloged air
filter will cause the condition you describe.
Good luck with this, It has worked for me where the piston lift
method seemed vague and inconclusive.
>Or should I just forget it until I can take it some place where
>they have the know-how and the equipment?
Your call but if you enjoy dectective work, go for it. If you get stuck,
come back to the list with more details.
Eugene Harrison
79B
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