crank put on TDC, key should be pointing downward at about the 4 or 5 o'clock position. Cam gear has a hole in the gear called the (dowel hole), that should be in the downward position aligned with the key in the crank in same orientation.

The chain may have identifying links that may align with any marks on the gears but the instructions i was looking at did not mention this, the K series times that way with the chain links and marks though.