I just went through an OC3 and getting it timed.  I found on the flywheel 2 stamps, one SPARK and a DC, both with a stamped line and about an inch or two apart.  With &quot;spark&quot; lined up the first cylinder is past center and &quot;DC&quot; is dead center.  Does anyone know about these marks?  I'm working by memory right now but I'm sure it's a &quot;DC&quot;. 

The next question I had was about the mag.  When I get number 1 to the top, I wanted to make sure that the needle should appear in the little window on the mag or if there is more to it.  

If it helps, This is an IXB3 motor with a water pump.  I think, based on what I've read, this machine is '51-55 based on the idler having an outside flange but no tags to date on the frame or bellhousing that I've found.  Thanks