I have a 1985 85hp Force outboard. I bought the boat used and it runs well. After a few runs on the lake I turned the key and heard the starter spinning but the bendix was not engaging. I opened the cover and saw that the spring, retaining collar and nut were off the top of the starter. I found all the pieces and tightened as best I could. Once home I cranked on the nut really good to get it to stay, but this last weekend it did the same thing. Any ideas as to how I can get that nut to stay on the top of the starter? I'm thinking about finding a lock nut and replacing the old one. Any advice is appreciated. Thanks,