3.0 mercruiser - Setting timing from scratch

Chemdawg

Petty Officer 2nd Class
Joined
Aug 31, 2013
Messages
112
Setting timing from scratch - Mercruiser 3.0

Hello everyone. I have a few questions here. I just rebuilt the distributor with new points, condenser, rotor, cap, etc. Pulled the mechanical advance apart, cleaned everything, and put it all back together. Now this isn't my first rodeo with points and condenser ignition, but for some odd reason or another, I'm having a brain fart here.

I want to start from ground zero. As if I pulled the distributor out and cranked the motor. ( I didn't, but I want to think that way)

1: I bring the #1 cylinder to TDC on it's compression stroke
2: Rotate the distributor till the points are on the #1 spot closed
3: Lock down distributor
4: Start and final timing with light.

Does this sound correct? Or am I off somewhere?

The problem I'm having is that I set the points at the .022 setting, and tried to start the motor, and it won't start. It floods, or backfires through the carb. I'm assuming I have the timing off. I have the manual, and I know the plug wires are in the correct spots. However, I'm thinking that there may be an issue with which cylinder is trying to fire first.
 

Chemdawg

Petty Officer 2nd Class
Joined
Aug 31, 2013
Messages
112
Hello everyone. I have a few questions here. I just rebuilt the distributor with new points, condenser, rotor, cap, etc. Pulled the mechanical advance apart, cleaned everything, and put it all back together. Now this isn't my first rodeo with points and condenser ignition, but for some odd reason or another, I'm having a brain fart here.

I want to start from ground zero. As if I pulled the distributor out and cranked the motor. ( I didn't, but I want to think that way)

1: I bring the #1 cylinder to TDC on it's compression stroke
2: Rotate the distributor till the points are on the #1 spot closed
3: Lock down distributor
4: Start and final timing with light.

Does this sound correct? Or am I off somewhere?

The problem I'm having is that I set the points at the .022 setting, and tried to start the motor, and it won't start. It floods, or backfires through the carb. I'm assuming I have the timing off. I have the manual, and I know the plug wires are in the correct spots. However, I'm thinking that there may be an issue with which cylinder is trying to fire first.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,587
Pay no attention of where the points are, pay attention as to where the rotor is pointing. Set it up as you stated previously and turn the distributer where the rotor is pointing at No 1 cylinder. Keep the distributer just snug and you may have to turn it slightly as the engine is cranked. Make sure firing order is 1342
 

MikDee

Banned
Joined
Jun 6, 2007
Messages
4,745
First off you should have marked the base of the Dist. and the block for indexing later, AND, you should have taken note of where the rotor was when you took out the Dist., so that you could have put it back in the same place, preferably on Cyl#1. You probably failed to do that, but all is not lost.

Take out the Dizzy, bring the crank to TDC, (make sure it's on compression stroke of #1) by putting your finger, hose, or compression gauge in #1, then drop your Dizzy in with the rotor facing #1, then just snug down the Dizzy, and use a timing light as you turn the Dizzy to the timing specs of the motor, then tighten the Dizzy down all the way.
 

Chemdawg

Petty Officer 2nd Class
Joined
Aug 31, 2013
Messages
112
Thanks MikDee. That's what I was thinking. I did mark the distro, but here is what I did. Like an idiot...... When I put the points in, the distro lobe was NOT on a high spot. So I loosened the distro and turned it till it was on a high spot. I did mark it though. Then set the points, and rotated the distro back to it's original spot. Now I'm not able to start at all. I know what I gotta do now. I will post back with my results.

Thanks for the info.
 

stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,827
Well, your coil fires when your points OPEN so at TDC compression your points should be open not closed. Not a 3.0 guy but with a "few" degrees advance the points should open just before TDC. You have a clockwise distributor so rotate the distributor CCW to advance the timing.
 
Last edited:

Chemdawg

Petty Officer 2nd Class
Joined
Aug 31, 2013
Messages
112
I was off a bit on the timing. I brought first piston to top dead center on the compression stroke, took out the distributor, and turned it till it was on the #1 piston, and it fired right up. Put on the old timing light, and tweaked it till it's at the 6deg BTDC like the manual says. Runs really well now.

Now if I could get this darn oil leak to stop at the drain plug.
 
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