Rusty timing tab???

[greiffster]

I have an occasional warm start issue that requires a few extra seconds of crank and an occasional dieseling after coming off near WOT. Yes, it helps if I let if idle a minute or so before I shut it down and with a little extra throttle the warm start problem is minimal. But I figure I'll check timing, idle speed, etc. just the same...

Alright, so I got a '96 5.0L Mercruiser with a rusty timing tab. I have attached a photo of it. How can I determine where 8 deg btdc is? Based on the figure on 4B-12 in the service manual, I think I can get close. How close is close enough? It appeared that it was timed around 4 deg btdc and I have reset it to 8 deg. In the photo, it is timed to approximately 1/3 from the left edge of the tab.

-mike

 

[Don S]

Re: Rusty timing tab???

You actually have enough of your timing mark there to get the timing right on the money.
If you look at the diagram in the manual, you will see that the 0? mark is right at the top of the hole in the timing tab, and it goes out to an indent which I marked in Blue on your picture. You can also see the 8? ATDC point on your tab, I marked it in Yellow.
Turn your engine till the Timing mark on your vibration dampner is at 0? TDC, then make a new mark on the dampner at the 8? ATDC mark.
Now when you run the engine to set timing, you set the distributor with your new timing mark at 0? TDC which will actually be 8? BTDC.

 

[mc911]

Re: Rusty timing tab???

Hay
I tried to set the timing on my 89 omc 4.3 a few weeks ago but ran into a problem, my timing marks were gone. I bought a set of bolt on timing marks from my local NAPA dealer. You just remove 2 bolts from the timing chain cover and bolt the tab on. I didn't know there was such a thing. There were 2 available depending on if you have a 7" or 8" balancer. It was made by Mr.Gasket
The tab cost me $3.00 Canadian, so you should be able to get it for $1 In the States.
Hope this may help
Mark C

 

[greiffster]

Re: Rusty timing tab???

Thanks guys. I got her dialed in.

 

[greiffster]

Re: Rusty timing tab???

Given the distance to 8 deg before or after is the same from 0, I measured the distance from the marks in Don's diagram and used the same distance to scribe a new mark to the left for 8 deg BTDC. I then carried the mark up and scribed an additional mark on the motor for when the remainder of the tab rusts away.