Off to the Forest of Dean for the Crazy Horse rally this weekend. Decided to take the Velocette. Fairly uneventful ride there. Loads of beer Friday night. Start the bike in the morning - no problems. Go to set off on the run and it went thud. No compression and very stiff to turn over on the kickstart. So I went out in Huws sidecar. Again.
Got recovered home on Sunday morning (no point wasting a good weekend) and started to investigate.
Rocker cover off - no sign of damage - but nothing was moving when I turned the engine over.
Timing cover off and I found this:-
A bit of metal about 10mm square jammed between the crank pinnion and the intermediate timing pinnion.
This is where it came from:-
Its a BTH automatic ignition timing device. And they say X never marks the spot - it does this time. Not drawn by me I might add.
So the bit of metal has jammed the timing pinnions, shearing the crankshaft woodruff key. Complete engine strip down then. Again.