2002 Mercury 150hp Timing

Hello,

I plan to do a link and sync on my 2002 Mercury 150hp Saltwater series
ser#0T468962. It idles a little rough. I have various manuals but none exactlymatch this motor. My question is:

1)The Decal on the motor states 4BTDC\20BTDC. Is the 20BTDC timing
Cranking Speed or Wide Open Throttle? Could someone please tell me the
Cranking Speed or Wide Open Throttle timing?


2)I understand that the final idling timing will be set by adjusting the timing for proper idle RPM in gear in the water. How close to 4BTDC should I expect it to land.

Thanks,
Dennis
<!-- / message -->

I did a Link and Sync. I set the Idle timing in the water. It landed at "0"
at the proper Idle RPM.

Here is My question: The Decal on the motor states 4BTDC\20BTDC.

Does the 20BTDC refer to setting the timing by removing the plugs
excepting #1 and cranking the engine with MAX timing stop engaged or is the the timing at 5000+ RPM after the CM retards the timing?