I posted my previouse question and get discussion about timing test. I understod that I measured BTDC in write way. You can see this discussion on:
formatting link
PROBLEM: I just replaced Head Gasckets on Mercury Sable 1995, 3.8 liter engine. It had cooling liquid leak. The fuel consumption became 16 - 17 m/gal and was 20 -22m/gal before replacing. Engine runs good,When I set BTDC to 26 -27 degrees. If I try to turn distributer to bring BTDC to 10 degrees with SPOUT off (according to manuals) engine stops and can not start.Appreciate any thoughts ang gesses.