Proper info for timing a Merc 140

[MaxGlide]

1978 Mercruiser 140, serial number 3773776, electronic ignition upgrade.
Doing research and I am getting different info on how many degrees, BTDC, I need to set timing. Some say 8deg, some 6deg, some 4deg. Can the wise and all knowing group from this forum please set me straight?!
Thanks as always, for your time.
Wayne

 

[Alumarine]

For my 1974 which yours probably is it's 6 degrees BTDC at 650-700 rpm in gear.
That's with points.

 

[MaxGlide]

For my 1974 which yours probably is it's 6 degrees BTDC at 650-700 rpm in gear.
That's with points.

Thanks!

 

[MaxGlide]

1978 Mercruiser 140, serial number 3773776, electronic ignition upgrade.
Doing research and I am getting different info on how many degrees, BTDC, I need to set timing. Some say 8deg, some 6deg, some 4deg. Can the wise and all knowing group from this forum please set me straight?!
Thanks as always, for your time.
Wayne

EXTRA INFO. This is the distributor that is installed.

 

[Alumarine]

That looks like the standard points distributor with an electronic points eliminator.

 

[MaxGlide]

That looks like the standard points distributor with an electronic points eliminator.

That’s correct.

 

[achris]

From the Merc Service manual (#2)...
(Having electronic points doesn't change the timing spec). Timing can be set with the engine running on flushers. The only things that need to be set with the boat in the water (running in forward gear) are idle speed and mixture.

 

[MaxGlide]

From the Merc Service manual (#2)...
(Having electronic points doesn't change the timing spec). Timing can be set with the engine running on flushers. The only things that need to be set with the boat in the water (running in forward gear) are idle speed and mixture.
View attachment 357919

Thanks!

 

[kenny nunez]

Always a good thing to check is the condition of the springs and counter weights under the breaker plate. The posts that support the springs and weights will sometimes work loose allowing the distributor to over advance the timing. The weights will actually contact the inside of the distributor body when that happens.