help needed!!!i have put my drive chain's back together(many many time's)and i cant for the life of me understand this system,it wont drive at the moment have tightened/loosened chain,now let me say this i am fairly handy with the spanner's but this f@%$%& thing has sent me crazy. how does the sprocket on the crankshaft stay on!! if i turn everything by hand (machine elevated)the sprocket just undoes with the movement, i have copied the setup of pics and part's manual, i have spent more time on this than i should have,
