Re: 4hp 1985? evinrude outboard.
Screw on the back and front comes off.
Along with the idle adjust and choke knob.
You can remove the lower cowling by lifting one half of the back- up, and the other side down. The maneuver it off.
then you can get to the top screws/bolt to remove the pull starter plate.
Once that's off, you can remove the throttle plate.
My dual 4hp setup:
Good luck changing the water pump. (seriously, I have done many WP jobs, it was by far the worst to do)