[Motofool]

The marks on the sprockets should align with the top machined surface of the cylinders' head when the flywheel is at mark 2T.
If timing is off, you will need to remove the CCT and manually jump the chain over the offending sprocket.

Yes, that rubber guide is worn.

As you cannot measure 20 links on the top section, you will need to use only 14 links.

For a new chain, each link should measure exactly 1/4 inch (6.3 mm); hence 14 spaces (15 pins) should measure exactly 3.5 inches (88.9 mm).

If you measure those 14 links under a tension of around 10 pounds (via rotating and keeping some torque on the cam-shafts in opposite directions), for several sections of the chain all the way around, and at least one section measures more than 3.55 inches (90.3 mm), then the chain has reached the end of its life.

When you replace the chain cover that you removed, you will need to torque those bolts at 104 in-lb.