Timing Info Needed for '85 140

[Jacalore]

Want to check timing on my 1985 MerCruiser 3.0L 140 with electronic ignition conversion kit installed by PO. No paperwork. Any info appreciated. Thanks.

 

[Don S]

Re: Timing Info Needed for '85 140

6? BTDC at idle rpm.

 

[Jacalore]

Re: Timing Info Needed for '85 140

Thanks, Don. Is that with jumpers?
And does elec ig change the timing?

 

[Jacalore]

Re: Timing Info Needed for '85 140

Ok, found info on engine tag 6?BTDC

But I see no wires to jumper out of distributor - just two (red & black)
Nor do I see the shift jumpers... can I set the timing on this engine w/o jumpers?

Also, how do I rotate the distributor housing if I need to make a timing adjustment?

Thanks for the assistance, I'm not a mechanic and feel like I'm flying at night w/o instruments!

 

[Don S]

Re: Timing Info Needed for '85 140

Assuming you have something like the pertronix conversion, no there is no jumping anything to set timing.

 

[Jacalore]

Re: Timing Info Needed for '85 140

I believe it is the Sierra conversion kit sold on this site. Does that make a difference?

 

[Jacalore]

Re: Timing Info Needed for '85 140

Do you know how hard it is to find a cheap timing light? Three auto supply stores (NAPA, Pep Boys, Advance)!
Just sayin...

 

[Don S]

Re: Timing Info Needed for '85 140

Do you know how hard it is to find a cheap timing light? Three auto supply stores (NAPA, Pep Boys, Advance)!
Just sayin...

Call them and ask. Use the phone.

 

[Jacalore]

Re: Timing Info Needed for '85 140

Nothing is easy, eh? Cleaned off the timing tab and there are no markings...
The tab has 6 evenly spaced points facing forward. So, either we are counting points or gaps? And which is TDC?
I assume the ones inward are 'before' and the outside ones are the 'after' ... just which one is TDC?
And is each point (or gap?) equal to 2 degrees?
Thanks

 

[Don S]

Re: Timing Info Needed for '85 140

There are several variations of that tab, below is one. If this one isn't the same as yours, post a clear picture of what you have and I can mark it for you. Like I did this one.

 

[Jacalore]

Re: Timing Info Needed for '85 140

Don, that looks exactly like mine!

Ok, so I'm ready to adj the timing. To be clear, there are no wires to jumper, switches to short?
In idle, read and adjust distributor housing to read 6 degrees BTDC?
Is there a loosing screw on the dist somewhere?

Thanks for all your help!!!

 

[UNSUREBOATGUY]

Re: Timing Info Needed for '85 140

There should be a bolt on a clamp on the bottom of the distributor. If you loosen it a little, it should turn. Turn just a tiny bit at a time-a little bit makes a difference. Good luck.

 

[Jacalore]

Re: Timing Info Needed for '85 140

Ok, making progress!
Checked the timing - it's reading TDC! So, this may be the cause of my problem.
BUT, I can't get at the bolt underneath the distributor. Looks to be about 1/2" and access blocked from the top by the dist housing, blocked at other angle by fuel pump, dipstick chute and fuel line. THIS is gonna be a challenge! There;s is only one bolt, so I assume this is the adjustment. Pic attached.

Which way to turn go 6? Before?

 

[Jacalore]

Re: Timing Info Needed for '85 140

Well, the timing is spot on, but stall at higher rpm problem still remains...
Q: The carb mix screw has no effect after about 1-1/2 turns out. The rpms rise about 3-1/2 turns out... any further adj has no affect. Turning idle screw puts the idle back down around 650-700 rpm. Idles a little rough. This doen't seem right? Any help appreciated. Thanks

 

[Jacalore]

Re: Timing Info Needed for '85 140

There are several variations of that tab, below is one. If this one isn't the same as yours, post a clear picture of what you have and I can mark it for you. Like I did this one.

View attachment 200007

Looks pretty much like that one, no? Just want to be sure. Thanks.

 

[Don S]

Re: Timing Info Needed for '85 140

Looks identical to me, you can see the 12 and the 0 in your picture when open to full size.

After you get the timing set, if you speed up the engine to say 3000 rpm, does the timing mark on the dampner move well above the 12 on the timing tab?

 

[Jacalore]

Re: Timing Info Needed for '85 140

can't get it up that high, stalls... if I mess with the mix adj, it stalls at different rpm (between 1200 - 2000)
the timing was set at 700 rpm, and it does advance as rpms increase.

 

[Don S]

Re: Timing Info Needed for '85 140

You probably have a carb issue, not an ignition issue.

 

[Jacalore]

Re: Timing Info Needed for '85 140

You probably have a carb issue, not an ignition issue.

I would agree with you, but this is the second carb... same symptom. I suppose it's possible...

 

[Jacalore]

Re: Timing Info Needed for '85 140

Is there a test I can do to isolate the carb as the prob?