1986 Merc 115 ELPTO electrical questions

I started having issues with my boat at the end of last year. It was getting harder and harder to start until my last trip and it would not start. I ended up taking it to get checked out and i was told it needs the wiriing to the power packs redone, new power packs and a new stator. He showed me where the wiring was bubbled and one wire was missing insulation in two places about an inch or so of bare wire. Is this enough to loose enough spark that the motor won't start? Im going to try to tackle this on my own since im outta work and don't have the 1200.00 quoted to fix it. I was told by another guy that I may not necessairily have to replace the packs mabye just the wiring. Im trying to figure out if this all should be done or if the wiring could just be replaced. I hoping some help from this forum and the service manual will get back on the water. Any and all feedback will be greatly appreciated.

Re: 1986 Merc 115 ELPTO electrical questions

I have the same motor. If you are missing insulation, that is not a good thing. If the wiring is corroded, then obviously it must be replaced, but that is not to say that you couldn't just splice in some new lengths instead of replacing the whole harness. It depends on the condition. Some pictures would be great!
The first order of business is to make sure that there are no broken wires!
Then move on to checking all the grounds screws especially on the packs and coils.
Not a bad idea to actually remove those screws one at a time and check for and clean off any corrosion. Replace all the wires and tighten up before removing the next one.

If you do not see any broken wires, tape up any exposed wiring as long as its not too badly corroded and do some tests.

Does it now start and run well?

If not then you will need to perform a spark test to begin with. You will need a spark tester and you will need to set it at 7/16". They are about $5.

If you find any coils that don't spark, try swapping them with a good coil from another cylinder.

If that fixes the no spark condition in that cylinder, then it would be safe to say the the original coil is bad. Verify by installing in the "good" cylinder you removed the good coil from and check to verify no spark.
If indeed it checks out bad, then you need to replace it.

If swapping with a good coil does not fix the problem, then you will need to purchase or make a DVA adapter for your multimeter and perform some tests of the stator and trigger...

Re: 1986 Merc 115 ELPTO electrical questions

1997;


Here is the parts list for your engine:

http://www.crowleymarine.com/mercury-outboard/278.cfm


and you will see harness assys under WIRING HARNESS AND IGNITION COIL

The larger harness is not available at Crowley but you can search online and here is one which is available:

http://www.hallbergmarine.com/Mercury-Parts/HARNESSASSYNLAA-Part-Number-8496188A4.html

Gerry

Re: 1986 Merc 115 ELPTO electrical questions

redjmp said:

I have the same motor. If you are missing insulation, that is not a good thing. If the wiring is corroded, then obviously it must be replaced, but that is not to say that you couldn't just splice in some new lengths instead of replacing the whole harness. It depends on the condition. Some pictures would be great!
The first order of business is to make sure that there are no broken wires!
Then move on to checking all the grounds screws especially on the packs and coils.
Not a bad idea to actually remove those screws one at a time and check for and clean off any corrosion. Replace all the wires and tighten up before removing the next one.

If you do not see any broken wires, tape up any exposed wiring as long as its not too badly corroded and do some tests.

Does it now start and run well?

If not then you will need to perform a spark test to begin with. You will need a spark tester and you will need to set it at 7/16". They are about $5.

If you find any coils that don't spark, try swapping them with a good coil from another cylinder.

If that fixes the no spark condition in that cylinder, then it would be safe to say the the original coil is bad. Verify by installing in the "good" cylinder you removed the good coil from and check to verify no spark.
If indeed it checks out bad, then you need to replace it.

If swapping with a good coil does not fix the problem, then you will need to purchase or make a DVA adapter for your multimeter and perform some tests of the stator and trigger...

Click to expand...

Hello red and thanks for the response. It would not start for me and I have not tried since my last trip last year when it left me high and dry at the ramp. It had been getting harder to start as time went on but i could usually get it started but would run down the batteries in the process cause it would take so long cranking it to get it started. I did remember the mechanic I took it to said it was only running on three cylinders and I think that's why stator needed replaced. I had a friend who is an auto mechanic and very good with wiring and he noticed my bottom power pack had a slight bulge where the part # is located on the plastic where it must have gotten hot. He said that's not good and for sure he would probably replace that pack.