but it didn't lunch my engine which is good. 
The valve timing did slip significantly however and I had to reset it.Unfortunately, the crankshaft end cap in the alternator housing was in very tight indeed and sheared when I tried to remove it. I just removed the cover to finish the valve timing and the bike now runs a treat (or at least as well as it ever did). The only problem I have left is how to replace this end cap to make future spannering easier. A good sized chunk of metal came off meaning that a hex bit no longer fits. Any suggestions?
Thanks.