Mercruiser 3.0 distributor replacement

[amcfall]

I purchased a kit to upgrade my 1988 3.0 from points to electronic using the genuine parts as shown here:

3.0L Delco Voyager EST Marine Electronic Distributor Kit

The instructions are great for the wiring & timing part but assume you know how to swap it. It looks pretty straightforward but I'd feel better if someone could answer a few dumb questions.

Whats the basic process of the R&R? It looks like there is a bent 'fork' that holds the assembly in. I assume that you loosen it slightly to change the timing and remove it completely to pull the assembly? Any tricks? It's never as easy as it sounds.

When reinstalling, do I simply position the metal tab on the new assembly the same way as the rotor on the old unit? I took photos of the guts of each. Wasn't sure how to align when reassembling for proper firing..

Thanks, I am hoping to do this and replace the plugs next weekend. The hope is to only have to set the timing once! I had to borrow the timing light.

 

[stonyloam]

Re: Mercruiser 3.0 distributor replacement

Whats the basic process of the R&R? It looks like there is a bent 'fork' that holds the assembly in. I assume that you loosen it slightly to change the timing and remove it completely to pull the assembly? Any tricks? It's never as easy as it sounds.

When reinstalling, do I simply position the metal tab on the new assembly the same way as the rotor on the old unit? I took photos of the guts of each. Wasn't sure how to align when reassembling for proper firing..

I believe that is pretty much it. I would bring the engine around to TDC compression so the rotor is pointed directly at the #1 plug wire then pull the old distributor (once you pull the old distributor, do not allow the engine to turn). #1 should be marked on the cap. Make a mark on the new distributor body directly below the #1 plug. The gears on the cam are cut at an angle so you will want to turn the rotor a little (~1/8 turn) CCW so that it will line up correctly when you put it in (may have to wiggle it a little), and so it will slip into the oil pump. Make sure the new rotor lines up with the mark you made and you should be good to go. Good luck.

 

[Don S]

Re: Mercruiser 3.0 distributor replacement

No matter how careful you are with putting the new distributor in, you are still going to have to put the new distributor into base timing mode and use a timing light to set the timing.
When you rewire your shift interrupt switch, make sure you use bullet connectors on both wires so you can disconnect them for setting the timing. On the points distributor, one of those wires goes to ground on the shift plate, and if you don't take it off, you will not get it to work right.

 

[fishrdan]

Re: Mercruiser 3.0 distributor replacement

On the dist clamp (fork thingy), tighten it down so the distributor is kind of hard to turn, but still turns,,, time the engine, then completely tighten the clamp and recheck timing (to make sure it didn't change).

so it will slip into the oil pump.

I'd have a long standard screw driver and flashlight handy, to turn the oil pump so it aligns with the distributor's oil pump drive tab.

 

[amcfall]

Re: Mercruiser 3.0 distributor replacement

Thanks for the tips all, great stuff. I appreciate it greatly. Hopefully I get the time to do this, plugs and a compression test Saturday. The warm weather last weekend is making me antsy....