I made a start on the Villiers Mk12 today, I noticed the governor had been broken off where the spring for the throttle connects. Whilst this didn't really worry me that much as I had the engine running like it. However, after removing the sump this afternoon I was greeted by some loose parts sat in the bottom of the engine! It would appear that the governor had possibly been snapped at some point whilst the engine was running, this then allowed the engine to 'run away' causing the governor gear and counterweights to self destruct! The brass counterweights are bent and twisted on the pivots and the 2 centre pins are bent over to about 20 degrees......... Thankfully the only damage these loose bits have caused is some very light scoring to the crank lobes. The crank and all other internals are perfectly good to use again.
It's a good job Alan and Chris persuaded me to take the spare MK12 sat at Johns! At least I have a source of spares!!!