Mistake in mercruiser manual?

[b0mbtrack]

4.3lMpi engine, 2003. I forget the number but it falls in the OM322781 and above ones.

Manual 32. On page 4b-13 they are showing what position the rotor has to be in when installing the distributor if the engine is at TDC. I got the engine over to the compression stroke TDC but where they wanted me to put the rotor was nowhere near (before or after) number one. I know on these caps you have to look underneath and follow the path in the housing to find out which tang belongs to which plug wire. So I did that and it seemed like it was on the opposite side. I double checked being on compression stroke and TDC and that was right but the rotor was still nowhere near where it should be. I noticed another mark on the distributor that looked like a better spot for it to be but the book didn't want it there. Luckily there was a twin engine that turned the same way (standard) so I got that engine at TDC compression stroke and saw where it's rotor was and it was at the opposite of what the book said. I'm just wondering if anyone is familiar with this, if the book is wrong or if I have something else going on. The engine worked fine after I set it up at the other mark.

 

[Don S]

Re: Mistake in mercruiser manual?

Are you sure you are finding TDC on the compression stroke the right way? http://forums.iboats.com/showthread.php?t=427081

#1 cylinder is port side of the engine on the front. Distributor in the rear.

 

[b0mbtrack]

Re: Mistake in mercruiser manual?

Yeah I've done this countless times, just not with this kind of distributor. I also use the finger over the hole trick to find the compression stroke and know the difference between the feeling of compression stroke vs exhaust stroke on my finger. There is also a very clear mark on the dampner where TDC is. I also stuck a bore scope down the plug hole to make sure that one was at TDC. I went over it a bunch of times to make sure I was doing it right. I figured the book was wrong after checking so many times.

 

[Don S]

Re: Mistake in mercruiser manual?

I assume both engines are running? If so obviously something is being overlooked and checked wrong. Have no idea what it is, but here is some info from a Volvo manual for a 4.3. Goes into a bit more detail of how the distributor installs.

View attachment 4.3 Dist install.pdf

 

[b0mbtrack]

Re: Mistake in mercruiser manual?

Yeah both engines are running fine. The top picture on page 51 that you sent me is where I ended up lining the rotor up. My merc manual though says to line it up at the tab before the flat part of the distributor.

 

[b0mbtrack]

Re: Mistake in mercruiser manual?

Maybe it's just a misprint in my book, do you have a merc version of what you just sent me. Like I said, mine is from book number 32.

 

[Don S]

Re: Mistake in mercruiser manual?

Here is from my Merc manual. Kind of light on the info.

View attachment Merc dist install.pdf

 

[b0mbtrack]

Re: Mistake in mercruiser manual?

Ok that is the same as my merc manual. But if you look at the Volvo manual you sent me you will see they are different. The volvo manual had the correct spot. As far as the merc picture, I ended up lining the rotor up at the tab located at about six o'clock in that picture instead of the tab it is saying to line it up at.

 

[Fishermark]

Re: Mistake in mercruiser manual?

That is curious. Just so it can be easily seen... here's the two photos:


First, the Volvo instructions:

Then the Mercruiser instructions:

 

[Fishermark]

Re: Mistake in mercruiser manual?

In re-reading the two manuals, I see that the Mercruiser picture describes where the rotor needs to be pointing BEFORE dropping the distributor into the hole. The rotor will turn as it drops.

The Volvo picture describes the rotor AFTER the distributor has fully seated. There's your difference.

 

[Don S]

Re: Mistake in mercruiser manual?

Found the problem. The Mercruiser manual is wrong. The Merc instructions show for a V8 engine, not a 4.3. I looked in the Merc V8 manual and sure enough, the V6 instructions are in the V8 manual :facepalm: Even to the point of showing the 6 stamped in the housing.
Here is from manual 31 (V8 MPI Engines)



Here is a picture of the V8 Volvo distributor, notice the 8 stamped on the housing.

 

[Fishermark]

Re: Mistake in mercruiser manual?

Don, the picture you have posted is the same as the other Mercruiser picture. It simply has the "6". Isn't the real difference as noted above - the before and after installation?

 

[Don S]

Re: Mistake in mercruiser manual?

Ok, Mercs V8 manual is correct, they just used the pictures from the V8 manual in the V6 manual.
Anyway, to make it easier to see, I made all the distributors the same size and rotated the same way. Now it's easier to visualize.

 

[b0mbtrack]

Re: Mistake in mercruiser manual?

Thanks Don for doing all the research, work, and clarifying it all. That pic you posted of them all really helped. Thought I was maybe doing something wrong, thanks again.

 

[Don S]

Re: Mistake in mercruiser manual?

Since I am no longer working for a Mercruiser dealer, I would bet that Mercruiser sent out updates to the dealer with the paper manuals. Probably just a sticker to put over the original image. Used to get those small changes all the time.

 

[b0mbtrack]

Re: Mistake in mercruiser manual?

I used to work for one as well. There used to be so many of them they never ended up in the books, just in a random folder filled with with them that no one ever looked at