The reason for dropping this post out is because I am aware people sometimes have difficulty with successfully locking the flywheel with the lock pin. It is possible to believe the lock pin is home when it is not; this is due to the way the alignment hole is set out on the flywheel where it is on a raised area and what actually happens is that the lock pin becomes wedged between the face of the raised area and the flywheel housing. To prevent this happening I use a borescope to bring the flywheel alignment hole into the centre of the flywheel casing alignment hole before inserting the lock pin which goes home with a little wiggle of a socket on the end of the crank.