Merc 150 v6 timing help !!!!

[speedman79]

I'm trying to check timing on my 1982 Mariner/Merc 150 serial 6127812. I've read a dozen different instructions on how to due this and I just don't get it.... I made a TDC guage by wrapping electrical tape around my dial caliper till it would thread into hole#1 - it's ghetto, but it's solid and it works...This motor does not have a flywheel cover so I bolted a metal pointer to an existing hole on the motor.
- I find TDC cylinder #1 and aligned 0 with my pointer
- I rotate counter clockwise past .462 and then clockwise back to .462 per the manual - what the hell is this for??? If .150 is 25* then what is .462 for?
- Reading other posts on snf I see people timing each cylinder - again I don't get it - for what? To see if there is variation? I just want to make sure the motor is not timed way off since the advance modules have been taken off. Please someone with patience explain it to me like I'm an idiot - b/c apparently I am.

[hydrostreamvking4m]

This is a link to help you out.
http://www.hydrostream.org/ArticleArchives/Timing.htm

[speedman79]

That was a little better than my Seloc manual - thanks! The only thing I didn't see any reference too is the .462 mark - what is the relevance of this marking? BTW - trying to check timing actually helped me find my issue - I have no spark on #1 and #4 - the coils are good - they workk fine with #2 and #3 wires on them - I'm guessing that means switch boxes but I'm not sure that it cant be related to a trigger too...your thoughts?

[Dave Strong]

.462 is just a number Merc uses and is marked on fishing moter flywheels, if that is aligned then the the rest of the timing marks should be correct.... in a perfect world. But really to be exact you need to check each cyl at max timing and set to the one that is lowest. But for your average stock motor the .462 will work most of time.



Dave

[speedman79]

I'm waiting for the "ah-hah" moment when I can grasp this - lol. How do you use .462 mark to time the motor - it would be like 40* advanced on cyl #1. Something is going right over my head...

[rock]

It is just a reference point to dial in the timing pointer location, nothing else. If you set the timer pointer with a dial indicator there is a potential inaccuracy of 2-3 degrees due to the dwell at the top of the rotation. Setting the pointer by the .462 mark is far more accurate.

Rock

[Hoss Marine Propellers]

BTW - trying to check timing actually helped me find my issue - I have no spark on #1 and #4 - the coils are good - they workk fine with #2 and #3 wires on them - I'm guessing that means switch boxes but I'm not sure that it cant be related to a trigger too...your thoughts?

Sounds like the trigger?
The trigger operates in pairs....... it fires 1 & 4, 2 & 5, 3 & 6 cylinders.

A quick way to test the trigger is change the leads coming out of the trigger where they attach to the switch boxes to another position (cylinder)
and see if the problem follows? This will tell you the switch boxes are good and it's definitely the trigger.

[speedman79]

Sounds like the trigger?
The trigger operates in pairs....... it fires 1 & 4, 2 & 5, 3 & 6 cylinders.

A quick way to test the trigger is change the leads coming out of the trigger where they attach to the switch boxes to another position (cylinder)
and see if the problem follows? This will tell you the switch boxes are good and it's definitely the trigger.

Thank you! I didn't know that about the trigger but I suspected something maybe going on with it like that. I'll check that - never pulled a flywheel on any of my outboards before... hope its not to bad - any tips? I've heard you can pry it up a little and tap the shaft with a hammer to break the taper?

[speedman79]

UMMMM..... I just had a thought - spliced the brown wires from the trigger for BOTH packs because the insulation was so deteriorated. I used a crimp connector and sealed it up with that liquid electrical insulation - like DIP IT.. I have faith in splice but maybe it too much resistance and not doing the job.... I'm researching how to test the trigger - do I test resistance or voltage on trigger wires? Do I disconnect from the packs to test them?

[speedman79]

Just found this and heading outside.
http://www.cdielectronics.com/InstallSheet/134-6456.pdf

[Hoss Marine Propellers]

With a 30 year old motor, you're going to have problems with more of the wiring.
Check everything out visually ...... the other components may be working fine now, but will fail later.
Just give you a heads up about what might need to be replaced in the future & costs.

The Merc flywheel puller is the best & easiest......
You can take three bolts out of the flywheel & use a puller. I would be very careful about prying on anything.
If something breaks...... more $$$$$.

Mark the location of the stator & stator bolts so they go back on the same way.

After you replace the trigger assembly, you will have to do a complete timing/synchronise procedure.
(It's easy, if you know what you're doing????.... if not, people REALLY get them screwed up!)

[speedman79]

Turns out this was not a bad trigger. I replaced a brown wire from the trigger for cyl 1 and somehow the 5" section I replaced had a break in it... it was spliced well and soldered at both ends (ring and the splice) but the wire was broken INSIDE the insulation. It must have been when I stripped it I yanked to hard . I fixed it and it now has spark again. Problem is that I created this issue AFTER I came home from my troubled run on Saturday so this may not have been my prob. I checked timing and it was good -low if anything 18* at max advance. I posted in another thread that the motor was bogging to the point of not being able to plane off. Then all the sudden it would wake up and take off.... It's possible the brown wire I fixed was grounding out since it was pinched between the switch boxes but I won't know until I go back out and test it... I found that I have non matching switch boxes - 1 CDI and 1 Merc - not cool I know...