Lawn mower goes out after 2-3 meters.

Hello friends. I have an MTD lawnmower and since yesterday I have a problem. As soon as I press the drive handle (hope the name so) then the lawnmower drives 2-3 meters then it goes out! Without the drive I can mow quite “normal” lawn, only I have to push the lawnmower. What could this be about? Thank you!