Timing marks corroded on Merc 3.0L

[ezjam]

The timing marks on my 1994 Mercruiser 3.L are corroded. All I see is 6 triangular teeth. (Currently my engine idles at the 4th tooth from the "bottom".)

Can anybody shed some light as to what numbers correspond with what tooth?

Thanx in advance to all who reply.

ezjam

 

[firehog6305]

Re: Timing marks corroded on Merc 3.0L

on the merc 3.0lit isn't there a larger 'V' tooth as you call it?? the largest V is top dead center

 

[Don S]

Re: Timing marks corroded on Merc 3.0L

 

[ezjam]

Re: Timing marks corroded on Merc 3.0L

Thanx Don S... however mine looks a bit different. I don't have a deep groove. Check out this pic...

Safe to assume that the 3rd tooth from the bottom corresponds to your diagrams deep groove and thus is TDC?

 

[Don S]

Re: Timing marks corroded on Merc 3.0L

Safe to assume that the 3rd tooth from the bottom corresponds to your diagrams deep groove and thus is TDC?

Yes.

 

[ezjam]

Re: Timing marks corroded on Merc 3.0L

Thanx Don S.

Based on this info, my engine is running at 4 BTDC. Not where it should be. Might explain why I'm seeing dieseling.

Thanx again, I'm going to try to adjust.

ez

 

[Don S]

Re: Timing marks corroded on Merc 3.0L

Ahhhhh, now you have a problem that may not be your timing. Besides, when you checked the timing, and assuming you have the EST distributor, did you put it in base timing mode and set it to EXACT specs? If not, you aren't doing it right.
Besides, on a 3.0L the 2 most common reasons for dieseling is to high an idle rpm, and not allowing the engine to idle for a minute or two before shutting off.

 

[ezjam]

Re: Timing marks corroded on Merc 3.0L

Ahhhhh, now you have a problem that may not be your timing. Besides, when you checked the timing, and assuming you have the EST distributor, did you put it in base timing mode and set it to EXACT specs? If not, you aren't doing it right.
Besides, on a 3.0L the 2 most common reasons for dieseling is to high an idle rpm, and not allowing the engine to idle for a minute or two before shutting off.

Let me back up a bit... the real issue I'm attempting to fix is this http://forums.iboats.com/showthread.php?t=217101

The boat had issues from the day I bought it 6 months ago. (I got it fairly cheap)

As of now, I have not modified timing at all. I do however, have the correct method for setting it. (I have a Clymer manual.) However, based on that other thread, it appears to me that the very first thing I have to set before I set the timing is the idle speed. So tomorrow, first things I will do is work on the idle speed and idle mixture and then check and adjust timing as necessary.

I will do some reading tonight as to how to set the idle speed, however, if you have some links to help me out I would greatly appreciate it.

My engine is the 4 piston Mercruiser 3.0L with EST. My boat is a 1994 Classic I/O Bayliner.

Thanx in advance.

ez

 

[MikDee]

Re: Timing marks corroded on Merc 3.0L

You should be able to clean this up with some 400 wet sandpaper, and then the marks should become visible, take some bright yellow model airplane paint (in the small glass jars), and using a small paintbrush, or an old nail polish brush (cleaned with nail polish remover), and paint the mark you need, for future reference, I've done this.

 

[ezjam]

Re: Timing marks corroded on Merc 3.0L

You should be able to clean this up with some 400 wet sandpaper, and then the marks should become visible, take some bright yellow model airplane paint (in the small glass jars), and using a small paintbrush, or an old nail polish brush (cleaned with nail polish remover), and paint the mark you need, for future reference, I've done this.

MikDee,

Little sandpaper and water cleaned it right up. Thanx for the advice. As Don confirmed above, TDC is 3rd tooth from the bottom.

ez