In a message dated 97-03-14 11:53:38 EST, msmall(at)roanoke.infi.net (Marc James
Small) writes:
...to centralize the jet:
>
>loosen the outer brass bushing on the bottom of the carb a bit (not a lot or
>it will leak petrol all over that hot exhaust manifold)
>
>manually exercize the piston up and down a number of times until it falls
>with a metallic tap -- you have now centered the jet holder so that it is
>not contacting the needle
>
>
My own method of "manually exercising the piston up-and-down" is, with the
carbs OFF the car, to loosen the outer brass bushing as above, then to
vigorously shake the manifold and carbs as a unit up and down, hard enough to
hear the pistons make a good "whack" sound each time they hit bottom. (Having
the carbs completely off the manifold and shaking them individually is much
easier, but that probably means you're doing a complete rebuild)
I've found that I have to shake them again after progressively re-tightening
the outer brass jet holder a turn or two at a time. Sometimes you'll have to
loosen it again slightly. When the piston still moves easily with both outer
holder and the jet turned up tight, then you can back off the jet to the
usual setting and be assured of no interference.
Doing it on the car works sometimes, but it can be tough to build up enough
velocity to jostle the jet into position by just pushing the piston up and
down with a screwdriver or similar implement stuck in the tiny hole on the
front of the piston. You might be better off sticking a small mirror into
the carb to see which direction the needle is binding in the jet, then take
the top off the carb, pull the piston out, and simply push the jet the
direction you want and reassemble. (When looking at the jet from directly
above, you might notice that the jet is not exactly centered in the holder.
If the needle isn't bent, just visually centering the jet in the holder
often does the trick.) When re-assembling, remember to locate the diaphram
tabs.
Finally, as a last resort, some fine-tuning can be done on tough jobs by
varying the tightness of the four screws holding the carb top.
Dick Sanders
Seattle, WA
B395009510
B395005413
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