Just a tale for fun bathroom reading was cruising along, close to home when I heard an intermittent clanging noise. Passenger side of the motor it seemed. Limped it in and shut it off. Pulled the valve covers as I was going to adjust anyway, and thought perhaps something with the valves. All looked reasonable in there, but pulled all the rockers, inspected the push rods, etc. Put it back together and adjusted. Started quickly. Still noise. Pulled plugs from each cylinder and found a plug bent. crap. Is the cylinder hitting it? Put in a new plug. cycled the motor by hand, didn't feel it touch the plug. Hrm... Compression tested. 130psi. so thinking not a broken ring , hole in piston whatever Put a new plug. started .... clang.... Left the plug out and started on 7 cylinders. One clang then whoosh whoosh no noise other than compression..... Put plug back in. All was good. Something in cylinder that blew out. So what was it. Searched my driveway and found a possible contender. hrm definitely chewed up, not rounded so thinking not piece of valve, ring, what have you. Must have sucked something in, and def small screw sized....... Looked in the carb (easy to locate as with the Offy intake that 1 carb feeds the offending cyclinder. lo and behold see a hole where a screw should be in the throttle plate. Went back in a re-peened all 4 carbs while replacing the missing screw. Motor running well. maintaining compression on that cylinder. Perhaps dodged a bullet. ran without the plug to blow out any metal. Stuck a magnet in as well. Any other thoughts?