I have a 1969 Merc 800 that I am having trouble setting the spark advance on. I have pulled plug number 1 to find TDC and then lined up the arrow on the distributor pulley with the solid line on the flywheel so far so good. I have then hooked up an inductive tming light to #1 to set the spark advance. This is where the trouble starts the spark is at about 70 degrees BTDC. I then turn the distributor as far as I can and get the timing mark to 27 degrees BTDC. The spark advance screw isn't long enough to rotate the distributor to where it has to be to get on the timing mark and then if I run the spark advance screw all the way in the dissy won't move. It is almost like the dissy is 30 degrees out of place. I have never had this motor running right so I don't know what has been done to it. I checked the rotor to see if it is moving free of the shaft but it seems tight. Any help would be greatly appreciated.
