The first
photo shows the stock intake. Pretty skanky.
The second
photo shows the rough porting in progress. I used a grinding point on a drill press to evenly remove metal. I used lots of spray lube on the grinder and on the carb to keep the grinding smooth.
The third
photo shows the finished rough grind. You can see how much metal was actually removed.
The fourth
photo shows the finished carb. The rough grind was smoothed with 320 then 400 wet emory cloth to remove all scratches. Then it was given a quick polish with white compound.
The last
photo shows close ups of before and after. The bore now merges smoothly with the lip.
Needle and jet adjustments are needed after this mod.
Make sure you keep the point and the carb oiled while you grind. The oil carries away the aluminum and keeps the grinder in good shape. Make sure you don't grind into the slide area or into the lip the choke sits on.