115 Merc No Fire On Plugs

[fishdan]

I Have A 1984 115 Hp Inline 6 Mercury Seri# 6526655 .
No Fire On Plugs 1-3-5 Anyone Else Having This Problem .
What Do I Need To Check ?

Thanks

 

[CraigC]

Re: 115 Merc No Fire On Plugs

I'm not positive here, does that use 2 switch boxes or just 1?

IF IT HAS 2 (like V6's use):
That's most likely going to be a switch box (also known as power pack) that's gone bad. I've seen it a few times. The quickest test I've heard of for it is to swap the wires from the trigger between the front and rear switch boxes, and if you've now got no spark on 2-4-6 it's the switch box. They always tell you to replace them in pairs.
(Note: I believe they're about $120 each or so online for CDI one's if you look around, depending on part # )
If that somehow doesn't act as I described, check trigger and stator - but those are unlikely candidates since those 3 cyls run off of one switch box.

 

[emckelvy]

Re: 115 Merc No Fire On Plugs

If you swap trigger wires and the problem moves to the other switchbox, it's not the switchbox that's bad, it's the trigger.

First thing to do is pull the kill wires, to make sure you don't have problems with kill switch or wiring.

You can take resistance readings on the stator and trigger to see if there are any issues there.

You can also swap stator wires or swap boxes. Swapping boxes is probably the most positive method short of having special test equipment.

Here's some good ADI ign troubleshooting info:

http://outboardparts.com/mercury/troubleshooting/troubleshooting10.htm

http://outboardparts.com/mercury/troubleshooting/troubleshooting11.htm

HTH..........ed

 

[WANTONSOUPGUY]

Re: 115 Merc No Fire On Plugs *QUESTION*

Re: 115 Merc No Fire On Plugs *QUESTION*

I have the same issue with the same motor, 86 Merc. 115hp. I swapped the power packs with each other, and I still have the Same issue...1,3,and 5 give no spark. That tells me it's not the packs. Does anyone know where I should go from here?

 

[CraigC]

Re: 115 Merc No Fire On Plugs

It could be the trigger - if you have a manual, follow the testing procedure for the trigger.
If you don't have a manual let me know and I'll look it up for you.