View single post by Mark Rosenbaum
 Posted: 05-17-2007 03:53 am
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Mark Rosenbaum

Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
(1) Ensure that the fuel float in each carb is set to the identical level (0.688" nominal), and that the same thickness washer (0.087") is used under each carb's fuel inlet valve ('needle valve').

(2) Ensure that both carbs use mixture needles bearing the identical identification code (B1CM for early cars, B1DK for later ones).  The needle identification code is stamped into the shaft just under the head of the needle, and may be viewed by pulling gently by hand on the needle shaft until the text becomes visible.

(3) Gauge the main metering jet (the brass tube in the carb body, into which the mixture needle fits) for size and wear.  A #40 (0.098" diameter) drill bit should always fit, a #39 (0.099") drill bit should be a tight to interference fit, and a #38 (0.101") drill bit should not fit.  Circularity of the hole may be readily estimated by inserting the #40 drill bit into the jet and holding the carburetor body up against a bright light.