Many riders neglect their Speedplays. They will wear out faster.
If they spin more than one turn when you spin them with your finger then they need lubrication.
A Speedplay Gun is best but you can use another gun if it has a small enough injector needle.
It must also have the correct grease. Non water soluble as specified by Speedplay.
You only have to remove the outer screw. Do not remove the plug.
Force the grease into the screw hole until it exudes from the spindle.
Make sure the plug remains in snug and replace the screw.
Wipe of excess grease. It takes about 2 minutes.
The pedal will now spin freely only about a half turn. This is correct.