1986 90 Six Cylinder Ignition Issue

[JDusza]

I have a 1986 90 hp vertical six that is not getting input to the ignition coils. #2 tested good out of the possible six. I used the input for #2 to verify the other coils would produce output. So, where should I go next?
Thanks,
J

 

[CharlieB]

Re: 1986 90 Six Cylinder Ignition Issue

Twin switchbox system, disconnect the white bias wires linking the two switchboxes and retest for spark.

DVA test all triggers, remember to disconnect the throttle cable and while cranking/testing, S L O W L Y move the throttle/timing lever to WOT and back to idle, causing the trigger wires to 'flex'. Broken yet abutted wires 'may' fire intermittantly.

DVA test stator.

Ensure starter is cranking at or above minimum 300 RPM necessary for system to function reliably.

If there is an extra white Bias wire leading to an idle stabilizer module, remove the module and trash it! Reset WOT timing to 21 degrees cranking.

 

[JDusza]

Re: 1986 90 Six Cylinder Ignition Issue

Thank you, Charlie.
I hope to pull the white wire tonight.
Can you coach me on meter readings? What should I be looking for, where? Continuity7? Voltages?
Appreciate the input.
J

 

[Sunfish12]

Re: 1986 90 Six Cylinder Ignition Issue

CDI Electronics has a test chart on their site with voltage specs.

 

[JDusza]

Re: 1986 90 Six Cylinder Ignition Issue

Pulled the white wire between the switch boxes. Same result; #2 fires, all others do not.
Off to the CDI website.
Thank.
J

 

[JDusza]

Re: 1986 90 Six Cylinder Ignition Issue

If I understand the CDI process correctly, if I swap input wires (red and blue) from switch box to switch box, I should be able to see if the dead switch box has any hope.
I am curious about the linkage to the trigger assembly, under the flywheel. It has a screw-adjustment linkage, however, this one is very loose, still. it seems to me that a screw adjustment linkage would be tense.
I could also switch the yellow wires on the rectifier to see if that is cooperating.
Any methods to verify flywheel is the right one and isn't weak or out of time?
Any other suggestions are appreciated.
Thanks,
J

 

[CharlieB]

Re: 1986 90 Six Cylinder Ignition Issue

The switchboxes are a 'Ground-to-Kill' using the Black wire with thin yellow stripe is the kill. Disconnect this wire from the switchboxes to the engine wireing harness and retest for spark as even a slight ground here can kill spark on most all cyls.

CDI test allow switching wires to see if a problem will move with the wire, hopefully isolating the problem. If that does not work you need either a DVA meter or DVA adaptor for your Volt/Ohm meter to measure the loaded voltage output of the stator and triggers.

 

[JDusza]

Re: 1986 90 Six Cylinder Ignition Issue

Thank you. I did forget about the ground-to-kill. I should detach those first before I dig deep.
I have a list of items to try.
I think I am without DVA adapter for my meter. I have a peak hold feature but I bet it can't capture what I need to see....
Thanks for hanging in there.
J

 

[Sunfish12]

Re: 1986 90 Six Cylinder Ignition Issue

No, the peak meter won't capture what you need, I built one with the specs from this site and it works great.

 

[JDusza]

Re: 1986 90 Six Cylinder Ignition Issue

Sunfish,
Can yuo point me in the direction of the specs?
Thanks.
J

 

[Sunfish12]

Re: 1986 90 Six Cylinder Ignition Issue

http://forums.iboats.com/showthread.php?t=371144
This should take you to the post.

 

[JDusza]

Re: 1986 90 Six Cylinder Ignition Issue

Thank you.
One thing I still do not understand is how to hook up the test leads properly. I find nothing that says how to hook up the DVA, the meter and the component to take a measurement.
Where do I connect the DVA test probes for measurements?
Should I disconnect the stator wires from the switch boxes to measure stator signals?
J

 

[JDusza]

Re: 1986 90 Six Cylinder Ignition Issue

Changed out the switch boxes and am back in the game!
Once again, thank you for the help. This forum is terrific.
J