Help with merc timing

[lbfd48]

I read somewhere that if I were to remove (which I did) the idle control box, little black box beside the fly wheel, that I would have to set the timing, 23deg @ wot. If this is correct, what is the safest way to do this? Should it be in the water or under a load? Its a 1985 merc 2.0 XR2, on the engine stand.

 

[Mark]

You probably should pick up a manual for that specific motor before you start messing with it. Some Mercs have modules that advance the spark (at higher RPMs) and some that are just idle stabilizers meaning they only advance the timing if RPM's drop below 550.
You need to make sure you know what you are dealing with first. It's not a good idea to guess when messing with the bias voltage.
It is a challenge timing a motor at WOT without a test wheel. You can disconnect the butterflies and manually advance the timing at idle to have a quick look with the timing light. Don't hold it there too long as it is not meant to run full advance at idle. A couple of seconds won't hurt it though.

 

[lbfd48]

Well, I have a book and the only thing it says is to set timing at cranking speed with the black box, it has nothing in it about removing it lol. Im pretty sure the idle box raises the timing 5 deg if it falls below 500rpm, and retards timing 5 deg after 5000rpm. So I need some input on the safest was to set timing.
Thanks, Jared