In article , Bmallory410.c1c4593
@boatbanter.com says...

I recently purchased a used 14 ft Jon boat with a 1959 18hp Johnson
seahorse outboard motor.... I just planned on using the boat for duck
hunting so I didn't really want to spend a lot of money. Everything is
good except the motor won't go into gear. The first day I bought it I
went to run it at the lake and it ran until the shear pin broke.... When
I got home i changed it and when I went back today to run it, it
wouldn't go into gear...when you pulled the shifter in either reverse or
forward nothing happened....prop wouldn't spin... Checked the shear pin
and it was good... It also won't rev up in neutral anymore either....any
ideas?

Go buy a 5HP motor and hang it off the back.