Re: 1990 40HP forward gear only?
Welcome to iboats kpudden.
First thing is pull the hood off the motor on the right side(drivers side) of the engine you should see 2 cables, 1 of these is the shift and the other the throttle, move the throttle at the helm and see if both cable ends move.
If only one cable moves you will need to replace your shift cable, if both move repost and we will go from there.
Oh start at the start ,is this a remote control motor or tiller?