On Sep 10, 9:45 am, "john" wrote:
"jamesgangnc" wrote in message

...

The adjustments are all related to idle and low speed operation. Doesn't
have anything to do with high speed operation.

BUT, my 4.3 would choke and bog when I slammed the throttle wide open.
Adjusting the mixture screw fixed that. It did not seem to do anything to
my full throttle.

A bog coming off idle could be a bad idle mixture. But that's not the
problem this guy has. The mixture screw you are talking about is the
idle mixture. It adjusts the fuel flow through the idle circuit in
the carb. When the plates are in the idle position there is not
enough air flow though the carb to draw gas from the main jets. The
idle circuit suppliments the gas supply at idle to maintain the right
mixture.