Dans

Hi Guys, My father has purchased a new project boat which came with a 90hp mariner 80s tower of power 😩. We have been diagnosing the engine to see if it is worth repairing along with the boat and by restore (motor) i mean service and run it for a year. Motor starts and runs which is all good but we were unable to select through any gears. I have since removed the lower unit to check it all out and probably replace impeller while it is off and have it on a bench, prop is siezed on and soaking for the night to be pulled off tomorrow. Upon checking gear selection as the cable was destroyed I get the following from the unit -Neutral - Prop free spins both directions - Forward - Drive shaft rotates the prop forward and backwards. Turn forward by hand and the prop clicks driveshaft doesn't move sounds like its rolling over the teeth. Turning backwards rotates driveshaft in opposite direction. Dog clutch slipping/not engaging teeth? - Reverse - Drive shaft rotates prop backwards and forwards. Turn prop in reverse by hand engages no clicking. Turn forwards rotates driveshaft in opposite direction. Seems ok. I have had a socket on the selector rod and i am fully engaging through the gears. No fluid has be removed or changed yet. Would the clicking indicate a worn dog clutch or gear? or does it simply need to engage under pressure/engine running - im actually unsure? Should the prop free spin in the opposite direction when in gear? Any help would be appreciated before dropping cash into this engine and having lower unit diagnosed and repaired. Cheers