Where is 8* BTDC??
 

I've exhausted my search options on all of the interwebs. I'm setting base timing on my Merc 350 MAG MPI. Its a 0L372*** era motor, year 1999. I found a million threads on how and have the service manual. I though I completely understood how to do this procedure until I went to do it. My issue is that I see my mark on the balancer and see the mark on the plastic timing cover, but doesn't this indicate TDC #1? Shouldn't there be a larger tab on the timing cover to indicate degrees BTDC and ATDC? I looked at google images and could find nothing. The timing cover is just a small "V" shaped notch. The balancer does not appear to have any other markings unless I'm missing them. Please help.

To make sure, what does your distributor cap / rotor look like ?

#1)
http://www.mercruiserparts.com/Merc/...MMON/13723.gif

or #2)
http://www.mercruiserparts.com/Merc/...OMMON/9801.gif

from TDC on the balancer ( should be a line 0 ) there should be small dash lines before and after TDC, if for go back four notches before the TDC line, that is 8* before, each dash line is 2*,

You can use a timing light with an advance knob, or if you don't have one or any marks, 8 degrees before would be about 9/16" to the right of the top dead center mark on the balancer (for an 8 inch balancer).

Thats the easiest way,,,,, but there should be another timing mark on the balancer as well

On some of the Vortec motors, there is not. There is a notch in the balancer for TDC, and a mark on the plastic timing cover, and that is it. I use an advance light and set the ECM to timing set mode with a scan tool to set these motors.

When I've run in to that (on cars), I just use my adjustable timing light to determine degrees (on the light, not the tab).

Doh - looks like I was late to the party.

Buy ya a timing tape. Their available at most auto parts stores. Make sure you get one for the correct diameter balancer. http://www.jegs.com/p/Mr-Gasket/Mr-G...46079/10002/-1

SB, my distributor is picture number 1. It does require that base timing be set for this model. My balancer does not appear to have any hatch marks. I am putting the ECM (MEFI 3) into base timing mode by jumping pins A And B at the diag connector. I don't have an advance timing light. I guess I'll pick up some balancer timing tape. Thanks for the all the advice. This is what I was missing. Funny that so many other threads here and forums ask how to set base timing but nobody asked this question.

hey guys i have the same problem except i have distributor in picture #2