for carburettor PHBGProduct descriptionIf the choke is pulled on starting up the scooter, the mix is enriched. The PHB carburettors also have a choke jet through which the mix can be further affected when the choke is pulled. We stock the DELL??ORTO jets for the PHB series in sizes 50 to 90. In addition, the following applies: The bigger the jet, the richer the mix that results. Conclusion: A useful detail for perfect tuning when on tickover. -TIP: The cable choke conversion kit (part no 40320000) makes using the choke on the PHB carburettor easier! OEM numbers (for comparisons):B09501.070 (MALOSSI)0950170 02 (DELLORTO)