Distributor Help!

[Gallf1]

Hey
1999 SeaRay 380DA with twin Mercruiser 454 MAG MPI's.....went to change the spark plug wires and I noticed that the Stbd and Port engines have the same cylinder wires going to different points on their respective distributor. I know the firing order is 1-8-4-3-6-5-7-2 for both motors? but not clear to which post on the distributor?
I have attached a crude drawing of the distributor and posts if someone could tell me which letter corresponds to which cylinder? A=? B=? C=? etc

For reference the distributor has the square timing module housing on the bottom which is facing the back of the motor and towards the front of the boat (Std SeaRay set up).

Thanks!!

 

[scoflaw]

Doesn't matter as long as the respective wires reach. Most of my v8's have #1 at the 5 0'clock position looking aft.

 

[Gallf1]

Doesn't matter as long as the respective wires reach. Most of my v8's have #1 at the 5 0'clock position looking aft.

So.....say for example Cylinder #1 can be on any post of the distributor?.....or are you saying the Cyclinder #1 is at 5 o'clock and then go from there?

 

[scoflaw]

Yes #1 can be anywhere but your rotor has to be indexed to point at it when #1 is at TDC on the compression stroke. Yes to your 2nd question.

 

[Gallf1]

Yes #1 can be anywhere but your rotor has to be indexed to point at it when #1 is at TDC on the compression stroke. Yes to your 2nd question.

Thx....Mechanic had previously set base timing to 8 degrees on both engines and they where running great, I was just doing some Preventative Maintenance by installing new plug wires. I am sure that timing is adjusted correctly, sounds like I need to verify which distributor post is #1 at TDC

 

[scoflaw]

just replace the wires 1 at a time with what's there. now if you pulled all the wires off your going to have to find your starting point

 

[Gallf1]

just replace the wires 1 at a time with what's there. now if you pulled all the wires off your going to have to find your starting point

Thx....I followed what was there on the Stbd motor but on the Port motor its different from the Stbd.....guess TDC on Port side was different than the Stbd side (as far as which Distributor post).

 

[Bt Doctur]

With mercruiser #1 on the dist cap goes to #1 plug

 

[Air O'Nautical]

Possibly the distributor at some point, was removed and replaced.
Depending upon the installer... it is possible that your wires on your port and starboard engine could start in a different location. The firing order will remain the same but the location of the number one spark plug wire could be different.
I’ll add a YouTube video link which describes installing or stabbing the distributor.

 

[Gallf1]

Possibly the distributor at some point, was removed and replaced.
Depending upon the installer... it is possible that your wires on your port and starboard engine could start in a different location. The firing order will remain the same but the location of the number one spark plug wire could be different.
I’ll add a YouTube video link which describes installing or stabbing the distributor.

Thx
These engines were rebuilt a few years ago (before I bought it)....you are correct in that the distributors appear to have been in different on each engine.

ling story short, I found TDC by measuring piston stroke on #1 and then took the distributor cap off and found where it was pointing to.

Both engines now have new OEM spark plug wires and they run great.

I am going to buy some labels for the wires just so that I don’t have to trace them back next time!

Thx to all

 

[HawkX66]

With mercruiser #1 on the dist cap goes to #1 plug

If the distributor was set correctly.

 

[HawkX66]

Thx
These engines were rebuilt a few years ago (before I bought it)....you are correct in that the distributors appear to have been in different on each engine.

ling story short, I found TDC by measuring piston stroke on #1 and then took the distributor cap off and found where it was pointing to.

Both engines now have new OEM spark plug wires and they run great.

I am going to buy some labels for the wires just so that I don’t have to trace them back next time!

Thx to all

Did you do it on the compression stroke? Otherwise it can be 180 degrees out.

 

[Gallf1]

Did you do it on the compression stroke? Otherwise it can be 180 degrees out.

Yup....almost made that mistake!

 

[Espos4]

Thx
These engines were rebuilt a few years ago (before I bought it)....you are correct in that the distributors appear to have been in different on each engine.

ling story short, I found TDC by measuring piston stroke on #1 and then took the distributor cap off and found where it was pointing to.

Both engines now have new OEM spark plug wires and they run great.

I am going to buy some labels for the wires just so that I don’t have to trace them back next time!

Thx to all

A paint pen works well for labeling the boots.