the throttle on my razor e300 feels sticky or doesn't spring back all the way after i let go.

Diagnosis

Dirt, dust, or moisture has gotten inside the thumb throttle mechanism, gumming up the spring return.

How to Fix It

Clean the throttle assembly.

1. Spray a small amount of electrical contact cleaner (not WD-40) into the seam around the moving part of the throttle.
2. Work the throttle lever back and forth dozens of times to disperse the cleaner and loosen debris.
3. Let it dry completely for a few minutes.

If That Didn't Work

The internal spring may have broken or become dislodged. You'll need to replace the entire throttle assembly, which is a simple plug-and-play component.

Heads Up

A sticky throttle is a major safety hazard. Don't ride the scooter until it snaps back reliably on its own.