incl. VAT plus shipping costs
Complete PHBH carburettor kit incl. intake manifold and small parts for Vespa PX and similar.
Replaces the standard carburettor used at the factory and allows better tuning of the engine.
The Dell'Orto SI carburettor used at the factory is suitable for demanding engine configurations (e.g. The PHBH carburettor type offered in this set is much easier to tune.
The conventionally constructed PHBH round slide carburettor reacts clearly to nozzle changes and quickly leads to a setup that is easy to drive. This is also very stable in changing weather conditions, which makes this carburettor type particularly suitable for beginners and all-weather drivers.
Another big advantage of this set is the longer intake travel.
This dampens any blow-back in the intake tract and ensures a clean throttle response even in the lower rev range.In addition, the torque curve often also benefits from the longer but larger intake cross-section.
The set can be easily driven to the frame with the standard intake hose using the intake funnel supplied. The intake noise is therefore only minimally louder than with a standard carburettor.
The YSN carburettors contained in this set correspond in almost all details to the original Dell'Orto carburettors. The quality is absolutely comparable to the Italian original and the parts are also 99% interchangeable. Only the gas slides are guided through a slightly longer centering pin in the carburettor. If Dell'Orto gas slides are to be used, this pin in the aluminium casting can simply be taken back a little.
The nozzle setup of the YSN carburettor is already roughly pre-tuned for use on a Vespa engine. Normally it is sufficient to adjust the main nozzle to the own engine. Here a low-priced main nozzle set is suitable for tuning. Basic rule: tune from grease to lean. This means that a deliberately too large main nozzle is chosen with which the engine begins to stutter when throttling. Then the main nozzle is reduced in size until the engine just doesn't stutter anymore as soon as you drive full throttle. This corresponds then to a main nozzle size which means the maximum security for the cylinder. For best performance the mixture can be further reduced from this point via a smaller main nozzle. As rough guide values for rotary vane motors: Main nozzle size 120-135, diaphragm motors 125-145.
We offer the set in two versions:
for motors without separate lubrication (up to approx. 1983)
for motors with separate lubrication (from approx. 1984)
The sets differ only slightly in the scope of delivery. The set for motors with separate lubrication contains a plug to close the hole for the oil pump drive. The oil pump cannot be used.