This is my first post in MMT, and my first mud motor. I recently purchased a 5hp long tail mud motor from a guy at work. It kept throwing the keeper keys, plus it wasn't enough motor for my 1436. I had a 13hp honda gx390 that I recently had a guy mount on it for me. I took it out yesterday, and i was running like a champ, until the keeper key came out again... It's always the key on the shaft end of the u-joint that comes out. My set screws are tight and have lock-tight on them. I was told that it is an old go-devil frame. The 5hp wasn't the original motor on it. The prop looks brass almost, and it's the original prop. I'm pretty sure it's an older style prop. My question is have any of you guys had problems with the keeper keys coming out? Or am i the first one? I can't seem to get it to stay. Every time I run my boat, it throws the key. Not necessarily right off, but sometime in the trip it throws the key. If you guys have had this problem, how did you fix it?? I''m thinking about drilling a hole through the u-joint and shaft, and just putting a shear bolt in it. Any help/advice would be greatly appreciated. Like I said, this is my first mud motor.