Modern Vespa

First time poster - long time absorber of knowledge. I adjusted the needle height and cleaned out my jets on my Weber carb and once reassembled the engine will rev at high speed once I start the scoot. Inspect the throttle cable and I get good action at the needle. Also inspected the intake manifold for an leaks and to ensure it was firmly seated. Idle screw does not correct issue and twisting throttle while running does not increase engine rev. Any ideas my sage friends?

When you first start a scooter it is running on the bypass circuit controlled by what is commonly referred to as the choke. If it stays idling high after the choke gets hot then It's probably an air leak.

That is the symptom of an air leak. Even a manifold that looks god can have tiny cracks. A2001 original manifold will probably have a leak somewhere. Make sure all of your vacuum hoses are in good shape with no leaks. be sure the carb is tight in the manifold with no leaks. To test for leaks you can spray brake cleaner around the manifold as well as you carb and hoses, if the engine changes then that where the leak is. When I get an older scooter I always replace the manifold and hoses to be sure everything is good.

It could also be as simple as your idle is adjusted to high.

Why did you mess with the needle?? If you raised it, it's normal for the revs to be high. Needle is in the optimal position from factory. Unless it's a kitted engine there's no need to mess with the carb and its settings...

Thanks for the suggetions Pinkscooter and I was procrastinating on changing out the hoses so perhaps my ride was giving me a nudge, lol. I bought the ET2 from a third party and it always ran a bit rough so I pulled the carb to give it a deep cleaning and that's when I checked and noticed the needle height was not set at the factory position. It was actually at the third notch (higher) before I adjusted back to factory spec - I appreciate the input my friends. Cheers!