Draining gas from a Vespa gas tank is not as easy as draining gas from a car. Before you can drain gas from a Vespa scooter, it is often necessary to first remove its gas tank, especially in older scooter models. Special tools obtained from a Vespa parts supplier are also required to do the job. Chances are they may not be readily available in your neighbourhood car supply store.
Locate the steel gas tank under the Vespa's seat. Use a ratchet extension and a crow's foot wrench to remove its nut. If yours is a rear-mounted cap, you will need to modify the wrench to remove the nut and then the tank.
After the tank is removed, pour lacquer thinner into it, followed by ball bearings and nuts and bolts. Shake the tank. You can use the thinner alone if the tank isn't rusted or if fuel has not thickened.
Wear eye goggles and cleaning gloves. Plug the tank's hole with a cork and pour muriatic acid into it. Then screw the cap back on and shake the tank with vigour, if it is badly rusted. Next, drain the acid completely into a receptacle.
After the last drop of acid has been drained, dry out the tank with an air compressor or by spraying WD-40 into it.
Thoroughly inspect every inch of the tank, checking for rust holes or pinholes. If rust remains, including loose rust, repeat Steps 3 and 4. Make a final inspection and decide if your current tank is still usable or if it needs to be replaced with a new tank.
Finish the process for usable tanks by taking it to a professional who can seal its inside using correct sealers and sealing techniques. Do not attempt to do this process, as improper handling may damage your tank.
All Vespa gas tanks are located under the scooter's seat.
Old or bad fuel clogs the Vespa scooter's filter and carburettor. Do not let unused fuel sit inside your tank over long periods.