At 05:26 AM 7/31/2012, Hector Zapata wrote:
>I thought that was considered good for the mixture. Thirty-something
>years ago I met a mechanic who was very proud of the way he adjusted
>carburators, they frosted at idle, 80� weather...

Where the air pressure drops in the carburetor 
venturi, the temp also drops, and in cool damp 
weather the moisture will freeze out on the 
inside of the venturi in a layer that builds up 
and gradually strangles the engine.  Then you let 
it sit for a few minutes and the engine heat 
melts the ice and you get to do it again.  I 
learned about this the hard way in Vermont 
mountains in my Fiat 128 which had a lever on the 
air cleaner with a blue arrow and a red arrow, 
but no indication in the manual about what it was 
for.  It finally dawned on me that sliding the 
lever toward the red arrow would pull in some hot 
air from around the exhaust manifold, so I did 
that and hey presto, no more trouble that trip.

Yours,
David