Vincent dlima

When I pres the start button the dryer starts working. The moment I release the start button it stops. But If I keep the start switch pressing it keeps working fine. Completes the cycle.
So please advice what could be the problem.

Thanking you in anticipation.

The is a problem likely with the centrifugal switch that is suppose to keep the motor running. When the motor gets up to speed a centrifugal switch trips and closes points to complete the run circuit. I would imagine the contacts inside the switch are carboned up or broken.
Please watch this video for more detailed explanation.
https://www.youtube.com/watch?v=CaaqRXQERVc
You will need to replace the motor, here is yours
http://www.appliancepartspros.com/ge-kit-motor-and-we17x22217-ap5958529.html