1986 90hp inline-6, no spark trouble #5 cyl

[stewy65]

I just picked up a 1986 90hp, it's an inline 6 cylinder with a type-3 ignition system.I've been chasing an electrical bug thats kicking my butt and I could use a little insite if anyone has any. The initial problem was no spark on the number-5 cylinder, I first checked all the wires and grounds with no trouble found, next swapped the spark plug still no spark, swapped the coil, with the #4 coil (which sparks just fine) and still no spark on cyl-5, I next swapped the hot leads from the trigger to the upper swith box, I swapped the #5 cyl lead with the #1 cyl lead and now no spark on both cylinders, I put everything back to normal and now I still have no spark on the #1,#5 cyl. Theres really only two major components which are the trigger assembly and the switch box and both are expensive to replace.....has anyone out there dealt with this problem before and if so any advice you could give....what was the fix...is there anything else I could do? my gut is tellin me it's the trigger but that $200 flushed down the drain if it's not.

 

[Laddies]

Re: 1986 90hp inline-6, no spark trouble #5 cyl

A bad trigger will cause lose of spark on 2 cyls and can be cked with a OHM meter and a switch box will cause lose on 1 or more cyls.

 

[stewy65]

Re: 1986 90hp inline-6, no spark trouble #5 cyl

is it always two cyls with a faulty trigger??? or can it be just one cyl?? I just picked up the selco repair manual today and it doesn't specify, I'll measure the resistance tonight for the trigger. also the book has nothing trbl shootin the switch boxes. Thanks for the input

 

[Laddies]

Re: 1986 90hp inline-6, no spark trouble #5 cyl

The trigger on your engine is 3 windings and each end of the winding goes to a box one winding fires 1 & 2 the next fires 3 & 4 and the third fires 5 & 6 if any one of the windings are bad they have to effect the 2 cyls listed as the boxes are connected thru the bias circuit and act as each others ground

 

[stewy65]

Re: 1986 90hp inline-6, no spark trouble #5 cyl

so then if i have no spark on 1,5 it's more probable that the switch box is faulty, because they are not on the same trigger winding???

 

[Laddies]

Re: 1986 90hp inline-6, no spark trouble #5 cyl

Differant trigger winding and the same box so there is a were good chance it's the box

 

[stewy65]

Re: 1986 90hp inline-6, no spark trouble #5 cyl

thanks a million for the help, I'm interested in the ohm readings on the trigger, now the only issue is that this repair maual I bought does not have and trbl shooting procedure for the switch box or any specs for it. I guess I could just swap the boxes and see if the trbl follows. Thanks again for all help. If you have any more suggestions i'd be glad to hear them

 

[Laddies]

Re: 1986 90hp inline-6, no spark trouble #5 cyl

Without a DVA to test input and output it's imposable to test the boxes. Heres the test procedure from CDI

 

[stewy65]

Re: 1986 90hp inline-6, no spark trouble #5 cyl

SWEET!!!!! thanks for the info I picked up a compression tester and the selco repair manual this weekend, all 6 cyl have 125psi, so I continued trbl shooting. All the ohm readings for the trigger, stator, and coils were whithin spec, I swapped I guess what you would call the out wire from the switch box and the trbl follows so my best guess is that it is the switch box. As i was working on the engine I found another problem and I'm not sure if it's related at all but the two yellow wires going from the stator to the rectifier must have gotten real hot because i wiggled them and the insulation just crumpled right off....maybe the rectifier cooked at some point. Now I'm gonna have to remove the flywheel to see if I can somehow replace the two wires, or maybe even replace the stator which sucks because the ohms are all within spec and I'd hate to have to replace it just because the insulation was cooked off two of the wires.....figures just my luck, now I have to find a flywheel puller somewhere