This small pump is a wonderful thing indeed. It works via crankcase / cylinder pressure and guarantees a perfectly controlled flow of fuel to your carburettor. This is an almost ESSENTIAL bit of kit if you have a tuned engine in your Vespa or Lambretta. The Casa Lambretta Racing Teams scooters all use these with great success and they cured any fuel starvation problems encountered. The main body is made of aluminium making them extremely compact, lightweight and very robust.
- Flow Capacity : 35 lt./hr.
- Weight: 218 gr.
The pump works on pressure so to utilise this pump you will need to make two small modifications to make it work. Firstly, you will need to fit a breather valve stud (see Item: X18d) for the pressure needed to operate the pump. For reed-valved engines, this can be done on the side of the casting where the reedvalve sits (see pics). For NON reedvalved engines, this will need to be done either on the actual crankcase (near the bumpstop on top of the engine is fine), or on the side of the cylinder, where the transfers are (more difficult to do).
Secondly, another breather valve stud X18d is needed to provide an 'overflow' near the top of your petrol tank 'neck', for excess fuel to be returned back to the tank. This is done by simply drilling the top of the tank with an 8mm hole and fitting the stud.