Boat has been in the marina for a while and after we hired a diver to clean the bottom found a knocking
noise coming from the final drive. We have a Gori folding
propeller. After finding that the
propeller was not folding properly and was stuck in an partially extended position,We dived several times trying to clean the propeller.I finally I managed to remove the blade assembly. The gears of the folding prop were infested by lots of little shells (oysters?). Read online that soaking the prop in vinegar would soften the shells. After about a 2 hour soak in double strength vinegar the result was amazing. Now have sanded the prop with 80 grit paper to provide a key for Propspeed treatment. The fold works like new!