a little timing help please...

[liesight]

This question may sound dumb but I'm a novice at timing engines, on a omc 3.0l motor 1986...<br />1. when using a timing light at idle which tooth or dip do I use to time my engine, ya know the timing gauge looks kinda like sharks teeth, do I use the pointy side and if so which one, or do I use the indented ones, if so which one...<br /><br />2. In my manuel it says set the dwell from 31 degrees to 34, does it matter in this range what number to use, it seems my engine reacts to the slightest degreee change..<br /><br />3. Do I keep setting the timing mark and then adjust idel to about 600-700 rpm then repeat the process over and over?<br /><br />Any help would be great thanx a bunch.

 

[Boatist]

Re: a little timing help please...

You can set dwell anywhere in that range and should make no difference but if you can get 32 or 33 great. The dwell Just makes sure capacitor has time to charge and points to about .019. Make sure you set Dwell first as it will affect timing some.<br />Connect your timing light to plug one, front most. Adjust timing to 4 degrees before top dead center. My degree plate has the numbers on it so is easy. Zero degrees is on the point next noch up is 2 degrees point after that is 4 degrees. Make sure you adjust at idel speed. After have timing set you can adjust your idel speed to your disired setting.<br />How did you end up adjusting the Valves????

 

[liesight]

Re: a little timing help please...

Thanx for the resonse! Is your motor the same as mine? 3.0l OMC. I have multiple points on my degree plate, should I go from right to left or left to right? Which side brings me closer to 4 degrees btdc?<br />Thanx for any help.

 

[adrew]

Re: a little timing help please...

liesight, go back to a post dated sept. 28-02 or thereabouts titled "omc cobra 3.0 timing marks" and there you may find some information you seek. regards, adrew

 

[Bear]

Re: a little timing help please...

Here it is: omc cobra 3.0 timing marks

 

[liesight]

Re: a little timing help please...

I saw that page thanx, but the link for pics is broken, but I did end up sanding the rust off and whalla, timing marks on the engine, thanx for everyone's help.

 

[liesight]

Re: a little timing help please...

and BOASTIST, by the way, I ended up with a perfect valve lash adjustment, thanx to all that helped, I ended up just making sure the rods were tight and that there was no pre-load on the valve springs so that they had time to bleed, took the boat out today and it runs great, except for one problem, but I will ask for help after I try to figure it out on my own.<br /><br />thanx again

 

[Boatist]

Re: a little timing help please...

My motor is a little older a 1980 3.0L 181 cubic inch. My motor also has lots of degree markings markings. I not looking at it at the time but I think it goes from 8 degrees after top dead center to 20 degrees before top dead center. Glad you found the marks.<br />I am a little confused about your valve adjustment. Do you mean you adjusted just to point where push rod is tight and no slack in rocker arm, the point I would call zero gap?? If that is what you did engine will run there ok but will not have as much power or top end. At low RPMs will be fine. Proper adjustment would be one turn down from that point. Remember your motor has hydrolic lifters. The valve lifter is a like a cup with a spring in the bottom then a plunger on top of the spring and a clip to hold it all together. The cup has engine oil pumped into it to cushion the impact of opening the valves. Proper adjustment is to center the plunger between where it bottom out and where it hits the clip at the top. If you just adjusted to where the push rod become snug or zero clearance then when the cam tries to open the vlave what happeneds in spring in valve lifter is compressed but the valve does not move until lifter reaches the bottom. This does two things, makes the valve timing a little late and valve does not open as far as it should. You will loose power and top speed. At least it is running good for you.