What we found was prior to applying the tension, make sure the timing marks are lined up on the RHS perfect and on the LHS is at 5 past 3 so that when you apply the tension it pulls the LHS to 3 o clock. What you find is the top cam is bang on its lobe and it has a habit of jumping.
LHS - Cyl 2 & 4 on the near side (battery side)
RHS - Cyl 1 & 3 on the off side (air filter side)