I have a stock 1600 with a Weber progressive 32/36 DF AV. I am about to rebuild it and I started to wonder. There are two holes in the intake one small and one large. What is the correct installation of the intake? With the large hole by the fan (ie front) or with it facing the rear. Or does it make a difference.
I did notice that plugs 2 and 4 were quite carboned up, where as 1 and 3 looked lean/ok.
Compression was 1-120, 2-130,3-130, 4-120. I was getting a bunch of backfiring when I let off the gas so that is why I thought it was time to rebuild the carb.
Also while I’m at it what would be the proper jet size so someone living at 3,438 Ft. above sea level.
Executive Summary:
1- Location of intake manifold large hole in front or in rear?
2-Proper jetting based on 3,438 ft above sea level for a 32/36 DFAV Weber progressive.