Sounds like you need to remove the wheels then the clip holding the drive gear and clean the key slot out, It's likey packed with dirt.
Careful removing the gear..... The spring and key can fall out, Powdered graphite is a good lubricant that won't attract sand.....
Originally Posted by piston slapper
You never learn anything until you admit you don't know it all...
"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!