Carburetor -YSN PHBL 25 BS- AW=30mm - with vacuum/oil connection - folding choke

YSN PHBL 25 BS carburetor with AW 30 mm

The YSN PHBL 25 carburetor corresponds to the original in almost every detail. With YSN, we have a very good and reliable manufacturer at our side who continues to produce the legendary carburetors for us. The quality is absolutely comparable to the Italian original and the parts are 99% interchangeable. Only the throttle slides are guided in the carburetor by a slightly longer centering pin. If Dell'Orto throttle slides are to be used, this pin in the cast aluminum can simply be retracted slightly.

A major advantage of the PHB carburetor is its simple and good tunability as well as its insensitivity to weather changes. The PHBL shows quite quickly and clearly whether the mixture is too rich or too lean. A Mikuni or Keihin carburettor usually runs surprisingly well even when tuned too lean, which can unfortunately quickly result in a sticky mixture.

On most scooter engines, the following basic jetting for the PHBL series has proven to be a good starting point:

• Mixing tube: AQ264
• Needle: D26
• Secondary jet: 60-65
• Main jet: 95-105
• Slider: 40 (lean)

If problems with the fuel supply are suspected, it is advisable to convert to a larger float needle valve.

BS carburetor = adjusting screws in suction direction left

The carburetor is supplied with the following equipment:

Main jet: 102
Secondary jet: 70
Needle: D22
Mixing tube: AQ266
Slide: 40