The PHBG is a really great carburetor for the more advanced tuner. It helps you squeeze extra horsepower out of that expensive speed kit you just installed. This is a clone of the Dellorto PHBG that everyone loves.
A little lesson on PHBG carbs. The first letter after the numbers: A means clamp on type mounting, B means rubber mounting, other letters were produced for specific applications and follow no rules The second letter is S for left, D for right as it refers to the side on the carb. where the mixture and throttle stop screws are.
For tuning tips, check out Garage. The worlds largest moped tuning database. Here are the list of the top builds in garage using this jet. Use Garage as a guide to what jet you need.
Some Dellorto 21mm PHBG Builds and the Jets they are using. 21mm PHBG Builds