Piaggio Zip – Full throttle problems.

Piaggio Zip – Full throttle problems.

Full throttle hesitation is a common problem with the Piaggio Zip 50cc 2 stroke scooter. Low speed response tends to be ok but when the throttle is opened beyond half way the engine dies and returns to idle. Sometimes stalling but usually resting back at idle as the throttle is released. This occurs when the engine is warm.

There are a number of potential causes to this problem. The nature of the symptoms suggest fuel starvation so this is a good place to start.

The fuel taps on these scooters have two connections. One is the outgoing fuel and one is the incoming vacuum line. This is connected to the inlet manifold. When the engine is started a vacuum is created that releases the diaphragm in the fuel tap allowing the fuel to flow.

1) Check that the fuel tap is working correctly.

2) Clean, check and thoroughly inspect your carburetor. The needle and main jet are a common cause of these problems.

3) Clean and check your air filter.

4) Check the correct operation of the choke. When started from cold after a few minutes you should notice that the revs drop as the automatic choke releases due to the engine reaching operating temperature. Poor operation of the choke can cause a number of different problems.

5) If after checking all these components check your spark plug and all components of the ignition system.

The technical talk section has been written to provide scooter technical advice, scooter technical help and scooter technical support.



  1. Reply

    boys piaggio zip 50 2 stoke goes well then blurs out no speed at full throttle.

    seems to over fuel
    solution disconnected wires from autochoke problem solved boy very happy

    1. Reply

      Great news, hope the article helped. Your comments appreciated.regards

  2. Reply

    Hi I have the same problem how do you disconnect the chock.

    1. Reply

      The choke is connected via a two pin electrical connector. The length of lead varies so anything from 150mm to 300mm from the choke body. Find the lead going to the choke and trace it back. The connector is often hidden in a plastic sleeve and cable tied at each end. Simply pull the connector apart.

  3. Reply

    how do you check if fuel tap or needle and seat are good.
    What do you have to remove cover wise

    1. Reply

      To check fuel tap apply a vacuum and confirm that fuel is flowing freely. Visually check the needle and seat. Usually a good clean is sufficient. Access can be gained by removing the cover from the seat bowl.

  4. Reply

    Would like to post here to say that this was the most helpful post on this problem which is in quite a few forums.
    10 yo piaggio zip – everything checked and told “fuel jet only option – could be labour intensive to get correct size” which at repair shop rates was not worth it. Asked him to take off the auto choke – which he did after pointing out “it’s not a repair, it’s a botch” but it did the trick, lol!

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