what is the timing degree for mercruiser 3.0 4cylinder engine

[potatoe]

if i switch my points ignition over to an electronic ignition, and pull distributor, to put in the new one, will it take it out of timing when i put in new distributor? if yes, is there an easy way to time it? thanks

 

[NYBo]

Re: timing question

Re: timing question

The first issue is to ensure that the distributor shaft is properly indexed. With the old distributor installed, rotate the crankshaft to the TDC timing mark, remove the distributor cap and note exactly where the rotor is pointing. Make some sort of mark somewhere on the engine (not the distributor body) to indicate the spot. Remove the old distributor. Note that the shaft will rotate as you remove it (every distributor I've seen has a helical drive gear). Insert the new distributor with the rotor pointing the same way as the old rotor did at the point when the drive gear cleared and the shaft stopped rotating. When the new distributor is seated, the rotor should now be pointing at the mark you made. (This is really a bit simpler than I've made it sound). DO NOT ALLOW THE CRANKSHAFT TO TURN UNTIL YOU HAVE THE NEW DISTRIBUTOR PROPERLY SEATED WITH THE SHAFT PROPERLY INDEXED!

The second issue is base timing. Orient the distributor housing so the rotor points to the #1 spark plug wire on the distributor cap. This should get the timing close enough for you to start the engine and fine-tune the timing with a timing light. It is extremely important that the timing be correct! Too retarded and performance really drops; too advanced and you get detonation under load, probably leading to major engine damage. This includes checking total mechanical advance. If you are using a brand new marine distributor, it should be fine, but make sure the mechanical advance mechanism moves smoothly.

 

[Silvertip]

Re: timing question

Re: timing question

To answer your question -- yes! Anytime you move the distributor, change points or remove and replace the distributor it it is essential that you time the engine.

 

[potatoe]

Re: timing question. what is the setting for timing light

Re: timing question. what is the setting for timing light

does anyone know the degree setting for the timing light is, once my base timing is done? mercruiser 3.0 4cyl, 1987

 

[potatoe]

what is the timing degree for mercruiser 3.0 4cylinder engine

once the base time is set. where do i want to set the timing light to, before or after? how many degrees? thanks 1987 mercruiser 3.0

 

[Bondo]

Re: what is the timing degree for mercruiser 3.0 4cylinder engine

Ayuh,.... Once you set the base timing, put the timing light away....

I think those motors run 4? or 6? Before tdc...

 

[Silvertip]

Re: timing question

Re: timing question

Base timing is NOT just setting the distributor in place. Base timing is what you set when you use a timing light. Did you not get any instructions with the electronic ignition system? Base timing is the timing minus any advance. Look on the engine -- there may be a label that indicates what timing is supposed to be. The instructions for your ignition system may require that you jumper some pins in a connector to place the ignitiion system iin base timing mode so you can actually set "base timing".

Lastly, you would get much better information had you posted this in the Mercruiser I/O forum.

 

[potatoe]

Re: timing question

Re: timing question

i already have it close and running, and wires bi-passed. im looking for the actual timing specs for the light. but think i found them on valve cover like you said. thanks

 

[tschmidty]

Re: what is the timing degree for mercruiser 3.0 4cylinder engine

6 degrees btdc.

 

[Don S]

Re: what is the timing degree for mercruiser 3.0 4cylinder engine

It really depends on what ignition system you are using. I see from one of your other posts this 87 engine block is put in a 2000 boat. Did you use the EST distributor? The 4? or 6? information is not for the EST distributor.

 

[Silvertip]

Re: timing question

Re: timing question

Timing specs are for the engine -- not the light. The light just shows "where" the timing mark is.

 

[Don S]

Re: timing question

Re: timing question

I merged your two seperate posts into one.

You REALLY need to post what ignition system you are trying to time.

 

[potatoe]

Re: what is the timing degree for mercruiser 3.0 4cylinder engine

im using the original electronic ignition that came on the original 2002 motor, 3.0. i know the points ignition (older engine) does read 6 degrees btdc, and the 2002 electric ignition motor reads 2 atdc. and now i have the new ignition on the older engine, and its running pretty good, but i cant get the diistributer tuned in with the light. it runs best around 10 btdc. when i try to turn the mark closer, it just gets worse and stalls out. could this be because the distributer is still in wrong? i have all wires jumped correctly. or unless the mark on the pulley is wrong. does that mark come from the factory, or does a mechanic or somone put that on after

 

[Don S]

Re: what is the timing degree for mercruiser 3.0 4cylinder engine

With the EST distributor, you have to put the distributor into base timing mode before you try to adjust it.
You will find the process of putting it into base timing mode in this link.
http://www.boatfix.com/merc/Servmanl/13/13B4R2.PDF
Just look at the last page. I would also use the timing mentioned in that discription (1? BTDC) since it's for older engines. Your 2002 engine had a different head.

 

[potatoe]

Re: what is the timing degree for mercruiser 3.0 4cylinder engine

i did get it into base time, and triple checked it. i even watched a video on youtube especially for 3.0 mercruisers. i jumped the 2 white wires from distributer, and bipassed the shift switch like the intructions said, but i still cant get the mark even close without it stalling or running bad. could the distributer be in wrong still? i dont understand this. like i said, it runs good, but at 10-12 degrees btdc. but i dont want to leave it like that if its wrong. what to do what to do..... i would like to get this timing issue done so i can get a little use out of the boat before winterizing it. thanks