Merc 7.5hp tiller lock

My 7.5hp mercury 2 stroke has had a water impeller change by previous owner. The tiller lock is now inoperative, could these be connected?

When you say tiller lock, do you mean tilt lock? Tiller is the handle with the throttle and has a screw down tightener on the end of it called the tiller lock. Tilt lock is the release lever found on the front on the mount bracket to keep the engine from kicking up when in reverse. If it is the tilt lock, then yes it could have been messed up when the impeller was changed. There is a linkage that goes from the lock mechanism down to the shift rod. It attaches to the shift rod with a plastic piece that sits on top of it when the lower unit is reassembled. If this plastic piece was broken or installed incorrectly, your tilt lock will not work. It is very easy to remove the lower unit on this model. Just unbolt the nut on the front leading edge just above the lower unit and the other is located on the bottom of the cavitation plate. It should slide right apart. There is not linkage to undo. Check the plastic pieced that sits on top of the shift rod and reassemble. Makes sure you get the water tube back in its hole.

Thanks,sorry I've taken so long to reply. Very useful.