johnson shift
I dont have the problem you describe. However I have changed the water pump on many johnson/evenrude motors. it sound like you have either a shift rod problem, or a transmission problem. if its a transmission, it will probably clunk (and has for some time), when going into gear. a shift rod problem is normally the problem. you will have to drop the lower unit to examine this. the shift rod is connected to the transmission lever w/ a screw, and it needs to be removed after the lower unit has been unbolted, about 3/4". unscrew the screw, and the lower unit should come apart. now check the shift lever. it should have 3 positions, and should when turning the main drive gear, the prop should spin in forward/(neutral)/reverse. Note the shift lever part of the lower unit is adjustable by rotating 360degrees (up/down). it is a royal pita to adjust this, and re-install the screw, and then bolt it back up, and see if you still have all gears. I would expect you to find a bent shift rod, from the top end, connecting to the lower unit lever. try and bend it back withou breaking this. and re-assemble. -I would install a new waterpump while you have it apart... hopefully its something much tricker like an electric interlock, or setting on the throttle where it wont let you engage reverse when thottle is high. before you unbolt the lower unit, try changing the oil... best of luck!
