1970's/80's merc L6 distributor trigger

[monk-monk]

Lets discuss this distributor trigger deal a little bit...i've seen replies to threads where people have lost a cylinder and some think it could be a dist trigger problem. I would like to sort this out so it doesn't happen to my motors! I have researched threads here on iboats about this topic and one really stood out...Clams Canino (whom i have personally met when he rebuilt my '72 1150)...and he states, "the electronics on these motors are either Pass or Fail"...meaning, they either work or they don't...now Wayne knows his stuff about these motors...BUT i come here with open ears...if someone thinks otherwise, that the trigger could fail on only a certain cylinder...then please submit your opinion and an indepth reason how and why this might be...i know the rotor disc controls the trigger coil...so why would the trigger fire for one cylinder but not another...just trying to sort this out...Thanks

 

[1979checkmate]

Re: 1970's/80's merc L6 distributor trigger

simple, one wire from the trigger gets corroded and shorts out. THe problem is that could fry the whole trigger, or at least the corresponding cylinder to the short at least. Unfortunately, with these motors, If one component goes bad, it could have a trickle effect. IE. If the stator gets fried, it could easily move down and fry the rectifier, aftwerwards it could ruin a good switchbox, and once one switchbox is bad, the likelihood of the second switchbox going bad is dramatically increased. This has an adverse affect on many of these inline owners and is one reason alot of people move to different motors. Owners are tired of constantly replacing rectifiers or switchboxes, when the problem is really the stator or another component.

EDIT: THis post has mostly to due with non-distributor cd systems (79+)

 

[Laddies]

Re: 1970's/80's merc L6 distributor trigger

On a battery power CD system, it is impossable for the trigger to not fire 1 cyl. if it works one 1 it will work on all of them. If the trigger disc breaks and does not damage the sensor on the trigger then you could lose 1 or more cyls, not very probably but possible, normally if you lose a cyl it's a bad wire or cap.

 

[monk-monk]

Re: 1970's/80's merc L6 distributor trigger

Thanks for your reply! I noticed the "EDIT" in your closing...SO, keep in mind, with this distributor ALL spark plugs receive voltage via the trigger from the SAME wire...there's only 3 wires going to the distrib...one is the signal wire to send voltage to the spark plugs...if there is a "short to ground" in the signal wire...it's not going to just decide to ground out any one given cylinder..it's going to ground out acrossed the board on all cylinders...Mmmm?

 

[monk-monk]

Re: 1970's/80's merc L6 distributor trigger

Thanks Laddies...good to hear from you! Trigger works or it doesn't...till im proven wrong...LOL!...previous replies got me to thinking about something though...we all know how deteriated the wire insulation can become on these motors...makes me wonder what might be happening inside my distributor body with the wire insulation...checking for voltage leaks in the dist wires isn't a bad idea at all...still thinking about one of those spark gap testers you spoke of...i'd like to know just how much voltage im getting at the plugs....

 

[monk-monk]

Re: 1970's/80's merc L6 distributor trigger

Sorry to post back-to-back on my thread J.B. and Crue, BUT i have to say one thing here: I started this Thread for educational purposes only..PERIOD...i read this, i read that...sometimes i just have to bring things "more to the point"....From experience (and i've worked on a bunch of stuff) i believe im right about this...BUT sometimes SOMEBODY KNOWS SOMETHING ABOUT SOMETHING...that might escape even the experienced...SO i wanted to define this topic...Im satisfied...LOL...!!

 

[Laddies]

Re: 1970's/80's merc L6 distributor trigger

monk-monk, a spark gap has a couple of proposes as far as I am concerned one it protects you against voltage and a multi cyl one that has adjustable gaps will let you compare voltage visibly. We recently bought a kilo-volt tester which can be helpful for some things how ever the maximum voltage output for the system is controlled by the condition of the plug, so I believe to capture max voltage one would need a oscilloscope