Is the ball joint itself bad or were the threads to secure it bad? I had a set of threads on my lower A-arms break and with a little work i put a ball and post from a 660 Raptor in my A-arm. 1992 Warrior though, without 'replaceable' ball joints.
Don't be discouraged if a simple oil change doesn't fix the hard to find neutral issue. I did a full engine/ trans rebuild, along with cleaning and reoiling the clutch plates, and neutral is a piece of cake to find. Cleaning up the clutch plates would be a good start to find neutral easier.
That screw is to check for oil flow while the engine is running. All you need to do is loosen it and if oil weeps out, then your oil pump is working. There isnt a lot of pressure and it shouldn't take much to torque it down. You'll want to use a reverse drill bit and hope to work the screw out...
Yes, you can put the Yamabond on there. I believe the O-ring is meant to handle all the oil sealing, but if you don't plan to open that cover to check valves for a while, you can add the sealant.
If its doing it with two different carburetors, then the carb is most likely not the problem. I would look at something electrical getting hot then shutting down. When cool the resistance value changes back to an acceptable range and it will work again. Likely an ignition coil.
I would drain the oil and fish around with a magnet if it doesnt drop out with the oil. There isnt very far a bolt can go inside. Taking the clutch cover off doesnt help, the bolt is in with the transmission components.
On second thought i don't think it can make it that far. The valves and cam lobes are sealed away from the rest of the motor, theres really nowhere for the nut to go down into the motor if im thinking correctly.
If you pull the stator cover off, it might be near the flywheel, or possibly made it to the lower end behind the flywheel. There is a hole big enough for the nut to fit in.
When I first got my Warrior I had the same problem. I ended up pulling the camshaft out and it was in the oil reservoir the cam lobes use to lubricate.
DRW Case Saver
Not the prettiest machine work, but is a tough material. It did not fit my 15 tooth front sprocket like advertised, so i had to do a little work to it. Would fit a 14 or smaller just fine. Cheap insurance.