Merc 140 timing made easy?

[MTBoat]

I want to reset the timing on my mercruiser 140.
1. I don't understand why one has to get the special wires to put it into base timing mode vs. just being able to set it at a certain degrees just the way it is?

In the old days we just set timing by ear and all was well.
2. What happens if I just set it, change the distributor position without the bypass using a timing light? Is it not possible?

3. After setting the timing, and once the bypass is removed, what is the degrees reading supposed to be then?

Why can't one just go for that setting without the little tool?

Thanks, I just don't have access to a store right now and need to make it run a bit smoother.

 

[fishrdan]

Re: Merc 140 timing made easy?

Have you swapped to an EST ignition, or are does the 140HP engine have the original points distributor? EST requires base timing mode, points dizzy does not. EST ignition was never used in a 140HP Mercruiser as the EST wasn't even made when the 140HP engines were in production. 3.0L Mercruiser yes, but not a 140HP Mercruiser

Setting the timing by "ear" can lead to things like,,, melted pistons, tuliped valves.... So yeah, it's best to set it correctly with a timing light.

 

[MTBoat]

Re: Merc 140 timing made easy?

Thanks, its a points dist. Do you know what the degrees are supposed to be on this unit? I guess I can just shoot it with a timing light and adjust the dist until I hit that number?

 

[fishrdan]

Re: Merc 140 timing made easy?

6* BTDC

Yes, just connect the timing light and set the timing to spec.