A fuel tap regulates the fuel flow between the tank and carburetor. The fuel filter keeps the engine clean. Both are small, but nevertheless crucial components for the reliable running of your Vespa. An upgrade or replacement is particularly worthwhile for old or tuned two-wheelers.
The function of the fuel tap
In principle, a fuel tap has a very simple design, but it has brilliant functions.
It sits directly on the tank, attached by means of a union nut.
- Open (ON/APERTURA). Normal operation, transports the fuel from the tank to the carburetor via a long tube
- Reserve (RES/APERTURA). If the fuel runs out before the driver has refueled, he/she switches the tank to reserve. A shorter tube for this purpose draws in the remaining fuel in the tank to continue supplying the carburetor with fuel. This small amount is usually sufficient to refuel directly at the next filling station
- Closed (OFF/CHIUSO). In this position, the fuel flow is completely interrupted. This position of the lever should be used if the two-wheeler is not in use for a longer period of time or has been taken out of service, for example in winter. It is also advisable to cut off the fuel supply permanently during maintenance/repair work so that no unintentional fuel leakage can occur
- Vent pipe; it protrudes into the tank and ensures that it is ventilated so that the mixture can flow smoothly
Occasional problems
Blockages, stiffness of the lever or leaks can lead to an obstruction of the fuel supply – the engine is undersupplied and runs unevenly. Porous seals can also cause fuel to leak out. Over time, the lever mechanism can become stiff due to ageing or contamination of the moving parts. If the strainer located in front of the tank opening on the fuel tap has done its job and caught dirt or rust particles, this dirt can act like a dam that hinders the smooth flow of fuel or makes it completely impossible.
A special fuel tap wrench is required to install and remove the fuel tap because the union nut is located deep in the tank and cannot be reached with conventional tools.
Fuel Tap Removal Wrench SIP for assembly/disassembly
For Vespa 50-125/PV/ET3/PK50-125/XL/XL2/125 V1-33/VN/VM/Hoffmann/ACMA/VNA-TS/150 VBA-T4/VL/VD/GS/PX80-200/PE/Lusso/’98/MY/’11/T5
- 32 mm
- angulate
- premium quality
Vespa models 125 VNA/VNB 1-2/150 VBA/T4, which have an original tank, require an offset fuel tap wrench with a wrench size of 22 mm. For the 160 GS and 180 SS models, on the other hand, a bent wrench must be used. To find out which wrench to use, it is best to shine a flashlight into the tank or consult the manual. Orientation point: Seat of the union nut.
SIP Fast Flow 2.0 fuel taps
They are based on newly designed molds. Advantages of the new designs:
- higher fuel flow rate
- smooth-running; design update without vent pipe
- Fuel tap lever with/without aluminum head freely selectable
- Available with sensor for reserve indicator
Fuel Tap SIP Fast Flow 2.0
For Vespa 50-125/PV/ET3/PK/S/125 V30-33/VM/VN/VNA-TS/150 VL/VB/GS/VBA-T4/160 GS/
180 SS/Rally/PX/T5
- Polished aluminum/black
- with reserve
- with lever L 200mm
Good to know: It is best to purchase a fuel tap wrench for installation and order a new fuel hose at the same time.
Fuel Tap SIP Fast Flow 2.0
For Vespa 50-125/PV/ET3/PK/S/125 V30-33/VM/VN/VNA-TS/150 VL/VB/GS/VBA-T4/160 GS/180 SS/Rally/PX/T5
- Without lever
- Electrical reserve indicator
- Filter net with ideal passage. Dirt and debris particles are safely trapped without reducing the flow rate.
The ventilation pipe introduced by Piaggio is no longer required.
Last, but not least: fuel filters
Fuel filters are available from SIP from various top brands: Malossi, RMS, Piaggio and Retro and cost between €2.00 and €8.00. The filters ensure that no unwanted dirt particles get into the carburetor. This is important for all scooters, whether vintage or tuned. The fuel filter is simply inserted into the fuel hose at any point between the carburetor and the tank.
Fuel taps and filters are among the most neglected parts of the scooter. Yet they are like the traffic police, except that they do not regulate road traffic, but the flow of fuel. Of course, we Vespisti are aware of the importance of such often neglected parts, which is why we always keep an eye on them to monitor their condition.
With this in mind: Have a safe journey at all times!
Video: SIP VESPA Fuel Tap Fastflow 2.0