Re: 2003 mercury xr6 max timing
If the heads arent shaved you should be able to run 25 degrees without the idle speed regulator hooked up. If the heads have had any shaving, drop a few degrees. The reconnect the idle speed control if you are into that sort of thing.
I like to disconnect the throttle at the carbs and then open up the throttle control full on while its idling on the muffs and then check the timing. Only runs up to 1600 RPM or so but the timing advances completely. Not quite textbook but the timing is spot on that way.