1) Turning the air mixture screw in (clockwise) closes an air bypass making
the mixture richer.
2) Has limited effect and only at idle
3) The O2 sensor should determine the final mixture after warm up.
4) Get the timing set properly. There is a procedure. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Danny
Sent: Friday, June 05, 2009 12:25 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Vanagon MPG

So I saw a post last week about every ones gas mileage. I posted that I was
getting 13 mile per gallon on a completely rebuilt engine (1984 westy
auto)�with just over 4000 miles. Someone e-mailed me saying that I should be
getting more than that. I checked my engine out and found the distributor
was loose and had turned an 1/8" or so. I knew this because when I got the
van back from the rebuild�I used a paint pen to make a mark on the
distributor and clamp just in case it ever moved I would know where it was.
So i moved it back and the exhaust smelt very rich so I turned my air
mixture screw in a few turns tell it did not smell so rich. Not only does my
van run with 30% more power, it is also smoother and now gets an easy 16
mile per gallon in the city. Thats an extra 36 miles per tank. What a
difference. O I did take it in to the mechanic to make sure my adjustments
were ok (the timing and the air flow meter) he checked the timing and it was
right on
 the money. Then he put it on what he called an infer-red gas analizer and
said the air mixture was also right on the money. 

Danny 
'84 Westy (Vanny)
�