Starting over on spark isues on 1985 Mariner 115

[chris0061]

In line 6 and I'll be counting coils from top 1 to bottom 6. I have fire on the top 3 coils. 1 and 3 go to the top switch box. 2 goes to the bottom. I was getting spark on number 5 which goes to the top switch box and nothing on 4 and 6 which goes to the bottom switch box. Now I'm not getting spark on 5 either so no spark on the bottom three coils and good spark on the top three. If both switch box's are giving spark in at least one coil and the trigger tested out good on resistance any Idea what could be going on here?

 

[phebus1]

Re: Starting over on spark isues on 1985 Mariner 115

Bottom three coils share a common ground point. Check to see if it is a good ground.

 

[Chris1956]

Re: Starting over on spark isues on 1985 Mariner 115

The CDIElectronics web site has a detailed troubleshooting procedure for that ADI ignition. I recomend you check into it.

 

[chris0061]

Re: Starting over on spark isues on 1985 Mariner 115

I did and from my limited experience everything is checking out OK on resistance. Not done and DVA yet. Have to get a meeter. Just strange that that pack of coils is not hitting.

 

[Chris1956]

Re: Starting over on spark isues on 1985 Mariner 115

Chris, You might want to restate the issue. Your first post is not entirely clear. You have spark on 1,3,5 but not 2,4,6? Or was it some other issue.

The way I understand it, the stator powers the coils in sets of two. The switchboxes power the coils in sets of three. That gives a clue where to test. Also the bias connection between the switchboxes has a function.

 

[Gomer50]

Re: Starting over on spark isues on 1985 Mariner 115

Same here ??? If you have spark on 2.4.6 but not on 1.3.5 switch the switchboxes around and see if spark follows,if they do!! bad switchbox.

 

[phebus1]

Re: Starting over on spark isues on 1985 Mariner 115

It sounds to me like he is getting spark to 1,2, and 3 (top three plugs) but no spark to 4, 5, and 6 (bottom three). If so, that would involve both switch boxes.

 

[brandon110]

Re: Starting over on spark isues on 1985 Mariner 115

Sounds to me like the bias circut. its a white wire (cant remember if it has a tracer) that connects to each switchbox OHMs test it if it tests ok id go with a new set of switchboxes. On just about all these motors that comes into my shop that has switchboxs with in ingition issue they get a set of new swtch boxes right off the back. they are very problematic and testing them i have found can be tough and time consuming. and if switchboxes do not fix it it gets a stator. I know it sounds like just throwing parts at a motor till its fixed but mercury has changed the switchboxes several times and unless you have the newest set of switchboxes there prone to fail at some point. good luck

 

[SparkieBoat]

Re: Starting over on spark isues on 1985 Mariner 115

links you need are in my sig..get a DVA adapter when you get tired of guessing.

 

[Faztbullet]

Re: Starting over on spark isues on 1985 Mariner 115

The way I understand it, the stator powers the coils in sets of two.

Not on a ADI system ... the stator function is to charge capacitor in switchbox. Its not your trigger as the pairing is off and is more likely the bias circuit in packs. Keeping it simple the bias circuit balances the - voltage to switchboxes so both are are in time and I suggest they both be replaced as this is a Merc recommendation.

 

[chris0061]

Re: Starting over on spark isues on 1985 Mariner 115

Well, today I switched out the switch boxes and went from getting fire on 4 plugs it went down to two. I'll be switching them back tomorrow and see what happens but I took the top off the engine cause I noticed the two yellow wires from the stator to the rectifier had tape on them and the wires are pretty much shot under the tape. Ive got the two switch boxes in the house here so when I go back at it tomorrow I will do a resistance check on the wires while they are all loose. I'm just about done guessing Faztbullet and looking for a DVA tester here in town but cant find one so guess I'll have to order one for my multimeter. I was getting spark to 1,2,3 and 5. When I switched the boxes I only got spark on 3 and 5. I should also mention when I was getting spark on 1,2 and 3, spark on 5 would be there sometimes and not be there sometimes. I'm going to order that dva tester and when I get it when I test the engine needs to be either running or at least cranking right?

 

[CharlieB]

Re: Starting over on spark isues on 1985 Mariner 115

Lost all my saved links when this box crashed last week so I can't give you the thread, but..........

Do a search here for a DIY DVA Adaptor

The diagrams and parts can be had for only a few bucks and will work with any volt/ohm meter.

Download the easy to follow directions in the FREE downloadable Ignition Troubleshooting Guide available on the Support pages of CDIElectronics

With the DVA Adaptor and your volt meter you will quickly solve your ignition problem.

Repost any questions you may have with the testing or your findings, as you have already learned, there is NO RETURN on electrical parts so you want to be doublel sure before spending any more without knowing that will cure your problem.

 

[chris0061]

Re: Starting over on spark isues on 1985 Mariner 115

will do, I ordered a DVA adapter tonight so will test with that when it gets here. I'll post findings.

 

[chris0061]

Re: Starting over on spark isues on 1985 Mariner 115

Went out this morning and put the switch boxes the way they were and hooked the wiring up per manual. When I took it apart the red/white and the blue/white were on the bottom switch box and the red and blue were on the top. Manual shoes opposite. Don't know if it makes any difference and I can see why it may have been hooked up that way cause the yellow indicator sleeve is on the blue/white and red/ white when it should be on the other two. But anyway now I have spark on all the odd which go to the top box and none on the even which go to the bottom box. Stator wires look bad as mentioned before so plan is new stator, two new switch boxes. And of course do the DVA testing when the meeter gets here but oms look right in range on everything.

 

[chris0061]

Re: Starting over on spark isues on 1985 Mariner 115

update. Today my new switch boxes came in and I put them in and it runs great above idle. It seems to want to miss at idle. you can see a puff of blue smoke come out with the exhaust every time it does. It is hitting on all cyl now though. I put a oms test to the coil wire + to eng ground and there is continuity between those on all the coils is this normal? Anyway you bring the motor past idle a little and it sounds great.

 

[M9.9]

Re: Starting over on spark isues on 1985 Mariner 115

Hi Chris and all,
Came up with the following older iboat link for building your own DVA Adapter:
http://forums.iboats.com/showthread.php?t=180482
In addition, You might consider making a spark tester, simple build. Good luck with your final fixes.

 

[chris0061]

Re: Starting over on spark isues on 1985 Mariner 115

got tired of guessing sparky. As noted earlier all cylinders are firing. Did the procdedure today as it was idling rough. here is the results. On the stator. [blue/blue-white] 7 k resistance on blue with 207 DVA. 7.23k resistance on blue-white with 110 DVA. [red/red-white] 158.4 resistance on red with 102-120 fluctuating DVA. 159resistance on red-white with 15.4 DVA. Looks way off according to the test specs. Trigger tests..... all resistance tests were right at 1265-1276 and DVA was from 8 volts to 10 volts. book said 4 volt or higher. Coils leads were reading low at about 90 volts on red and blue stator leads pack and 180 or so on red-white, blue-white stator leads pack so switched the stator leads around and the readings fallowed. so by the test looks like stator unless the DVA on the trigger leads is too high. Correct?????

 

[SparkieBoat]

Re: Starting over on spark isues on 1985 Mariner 115

just to be clear, I think the specs for blue to blue/white DVA is 180 or above this means one probe is on blue and the other on blue/white. then on red to red/white you should have 25 or higher. I am not exactly sure what you are reporting as the test above, you have 4 DVA readings and you should only have 2...skip the Resistance OHM test they are not reliable. there are 6 test for the trigger. read through the free CDI trouble shooting guide carefully and do each test until you find the culprit. link is in my sig below.. great job..you are becoming one of the most skilled outboard mechanics you know. you will be a huge help to a lot of friends.

 

[marzoid]

Re: Starting over on spark isues on 1985 Mariner 115

Hey I had a similar issue a little while ago. I have a 75hp 1985 merc
It ended up being an issue with the wires that go from the switchbox to the coils (harness)

I switched them around to the other ones and seen that the problems went to the other spark plugs thats how i figured it out

 

[chris0061]

Re: Starting over on spark isues on 1985 Mariner 115

I tested per outboard ignition.com. it showed read each to ground. blue 180 V or more and blue white 150 V or more. red and red white 25 volts or more. I did 6 tests on the trigger I just shortened the results above since the 3 resistance checks were close to the same and the 3 DVA tests were close to the same. I'm still not sure if there should be continuity between engine ground and the 6 coil leads. I can't find that answer anywhere and seems to me like there shouldn't be. I can retest tonight on the stator wire DVA testing them wire to wire.