Technology: Fast Flow installation made easy
In this video from our technical series, André shows how to fix a problem that many classic Vespa owners are familiar with: The Fuel Tap no longer wants to work as it should - perhaps quite normal when the vehicle is usually over 20 years old. Our expert André not only explains exactly how to fit a new fast-flow tap to the tank of a smallframe or largeframe Vespa, but also has a trick up his sleeve that means you don't even have to empty the contents of the tank for the repair.
There is a problem with the Vespa PX that we are using as a demonstration model: The Fuel Tap is either clogged, leaking or no longer works in the reserve position. In addition, the flow rate of the original Fuel Tap is often not sufficient for performance-enhanced Engines. This is why we replace the Fuel Tap with a new SIP Fast Flow Fuel Tap with electrical reserve indicator in the SIP speedometer.
The following parts and tools are required for the replacement:
New Fuel Tap (e.g. SIP Fast Flow, article 15878100 or -9100, without Lever 15878110 or -9110)
Fuel Tap Removal Wrench(32974100 for most models, 32975000 for VNA and VBA models, 98821000 for sports models with a large Tank: GS, SS and Rally)
New Fuel Hose(40281000 original Piaggio or e.g. 40281300 with steel spiral)
Hose Clips (original wire clamp 87017100 or e.g. 12309012 screw clamp with butterfly)
Rubber Frame(84262100 to protect the Fuel Hose at the exit from the bodywork)
Rivet, M8 hexagon socket head cap screw or Stud to seal the Fuel Hose during removal
Screwdriver or long rod to catch the Nut in the Tank
First, the petrol line on the Carburettor is disconnected and sealed or the Tank is emptied. The tank is then removed and André clamps it upright in a vice - this allows the fuel to collect in the lower part of the tank and the Fuel Tap can be replaced freely. The old Fuel Tap is loosened with a special spanner. The new Fuel Tap is then inserted and fitted hand-tight without pressing the Rubber Packing too hard. Please follow the enclosed Mounting Instruction for correct alignment.
The Fuel Hose is then fitted to the new tap using a Clamp. When laying the Inner Tube, follow the rule: "As short as possible, as long as necessary." Air bubbles in the system should be avoided at all costs. Finally, the electrical connection is made and the tap lever is attached. André shows how the tilt position of the tank moves the tap lever to the side and how the hole in the chassis of the Vespa is hit with the lever when the tank is inserted. Whether the Engine starts is the last check to ensure that the Carburettor is getting enough fuel.
Conclusion: Replacing the Fuel Tap and careful routing of the petrol line ensure sufficient fuel flow and reliable engine running - especially with performance-enhanced engines.
Video: Fast Flow installation
