Timing specs for 74 Merc 140

GUNNER9821

Cadet
Joined
Jul 22, 2007
Messages
6
Does anyone know or know where I can find the timing specs for a 74 Merc 140 inline 4? I am reasonably sure my timing is off, but do not know what to set it at.


Thank you,
 

95yj

Petty Officer 1st Class
Joined
Feb 21, 2007
Messages
279
Re: Timing specs for 74 Merc 140

Couldn't find a 1974. DonS will probably know off the top of his head.

1976 is probably the same. The 140HP is 6 Degrees BTDC @ 650-700 RPM. Plug gap is .035. Breaker point gap is .022 and dwell is 28-34 degrees. Breaker point spring tension 19-23 OZ. Preliminary Idle mixture 1.25 turns.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Timing specs for 74 Merc 140

from service manual #1, idle is 500-600, dwell is 31-34*, wot 4200-4600, timeing is 6* btdc, point gap is .022, plug gap .035, and spring tension @19-23oz
 

GUNNER9821

Cadet
Joined
Jul 22, 2007
Messages
6
Re: Timing specs for 74 Merc 140

Thank you for the information. As I expected it was off quite a bit. She is purring like a kitten at idle and roaring like a lion at wot. Thanks again for the assistance.
 
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