I did some looking around and found this write up Hope it helps....
In the hole on the side
of the right case the primary gear has a punch
mark that you align with the index mark on the case.
The camshaft sprocket has a timing mark that aligns
with the index mark on the camshaft holder. You can
just see the mark under the frame tube.
Align all the marks and install the sprocket bolts 14 ft/lbs
Turn the camshaft so the bolts go in but don't drop them in the engine! Recheck that all the marks align.
Don't open any valves when the piston is up, keep the camshaft
in a position to keep the valves closed when aligning the
marks to prevent damage.
For ignition timing there is a small timing hole on top near the dipstick.
Use a timing light and the "F" mark should align with the case mark