Started my '71 750 last week after a month without use and had an immediate loud clacking from the right hand cylinder head region. Thinking that it was due to it not being used for a while, I idled it for a minute or so with no change. To cut a long story short, It turns out that the right hand exhaust cam follower had lost the stellite pad into the crank case, which meant a complete strip down to find it broken in 3 pieces. Has any one heard of this happening before and could there be reason for it happening?