Mercruiser Setting Timing on 3.0L

[ESGWheel]

Yes
And to be clear at top dead center on its compression stroke

 

[DanOnTheBoat]

Yes
And to be clear at top dead center on its compression stroke

Makes sense. When Im on the compression stroke both valves will be on the same level? Also what if I didnt rotate the engine at all when it was taken apart, can I just adjust them now? Or its a must to have every cylinder ATDC compression stroke?

Update picture almost there

 

[ESGWheel]

Hopefully it has been clear to you based on my posts that in addition to guidance I also try to instruct. Said differently it is in my nature to teach. Perhaps you have heard the expression: "Give a man a fish, you feed him for a day; teach a man to fish, you feed him for a lifetime"

I know you want to learn so its time you fished. To help with that, I provide this video I found link.

Based on this and other info you have been given or have searched out, I would appreciate if you posted your own answer to your question.

And then I will reply to your answer as in that is correct or otherwise

 

[Bondo]

When Im on the compression stroke both valves will be on the same level? Also what if I didnt rotate the engine at all when it was taken apart, can I just adjust them now? Or its a must to have every cylinder ATDC compression stroke?

Ayuh,.... it doesn't matter whether you rotated the motor, or not,....
Now, you must rotate it to Tdc, compression stroke, on #1 to set the valves on #1,.... Then turn it to Tdc compression stroke, on each of the other cylinders,.....

I don't like the idea of turning the pushrods to find 0 lash, I gently lift 'em up, 'n down to find 0 lash, then tighten 3/4s turn tighter,....

Btw, it's Tdc,...... ATDC is where most motors have the ignition timed too,.....

 

[alldodge]

I don't like the idea of turning the pushrods to find 0 lash, I gently lift 'em up, 'n down to find 0 lash, then tighten 3/4s turn tighter,....

Agree up/down not turn, does not matter if you can turn it then it may be in the right spot but may also be just past it, based on how hard your turning. It can always be turned unless it's too tight already

Because everyone has one, here's mine
I don't bother with TDC other than when setting distributor in to get close to TDC prior to first start and adjustments.

I rotate crank and look for which valves are traveling down (opening valves). The valves that are open means the ones next to them are closed. I just the closed ones, make with grease pencil and rotate some more. Once all marked they are adjusted