Carburetor -DELLORTO PHBH 30 BS- AW=34mm

DELLORTO PHBH 30 BS carburetor with 34 mm connection width

The Dell'Orto PHB series has been on the market for many decades and has become an established name in the two-wheeler sector thanks to its versatility. The carburetors can be used in both two-stroke and four-stroke vehicles thanks to different mixing tubes. Due to the wide distribution of Dell'Orto carburettors, the supply of spare parts is also very good.

The somewhat outdated design has both advantages and disadvantages compared to a more modern counterpart. Its universal design makes this type of carburetor the perfect all-rounder, which is particularly suitable for everyday use. The disadvantage of the not particularly fine atomization compared to modern carburetors of Japanese design is ultimately also an advantage. A PHB carburetor works in all weathers and is a grateful candidate for tuning, as it quickly shows 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.

The following basic jetting has proven to be a good starting point on the vast majority of scooter engines:

• Mixing tube: AV264
• Needle: X2 or X3
• Secondary jet: 55
• Main jet: 120-150
• Slider: 30 (rich) or 40 (lean)

If problems with the fuel supply are suspected, it is advisable to upgrade to a larger float needle valve (#250).

BD carburetor = adjusting screws in suction direction right
BS carburetor = adjusting screws in suction direction left