Ignition wiring help request.

[FZ1]

Hi. 1986 Canadian NS400. purchased without hearing it run. I've been getting it ready to run over the winter,... its very low mileage and everything seems original at 19,000k. As it sits, it has spark on the lower left, the lower right, but not on the middle. Looking at the (online) service manual, this is spark on #1 and #2 but not #3. From the manual, #1 and #3 coils run from the larger (front) cdi, and the leftmost pulse coil. And #2 has its own pulse coil,
but contrary to the picture, of the two coils on the bracket on the right side under the cdi boxes, the innermost coil on my bike leads up to the center cylinder. Switching the wires between coils gives spark on the suspect coil,... which rules out a bad coil. I guess I'm just asking if there are errors on the service manual picture,... an explanation on the true cylinder numbering, and if this is a common problem?


Cheers

Grant

[FZ1]

Further investigation has revealed that the previous owner may have swapped the input wires on the #3 and #2 coils. I think now I've got spark on 1 and 3 but not one 2. I've tested #2 and it sparks when plugged into #3's wires. So i guess now I'm looking at either a #2 pickup coil or cdi unit, which as you well know are NLA from Honda. A little insight? or help on testing the CDI or trigger coil?

[Drys]

Did you carry out the tests of part 17 in the service manual?

[Mark]

Cylinders are numbered Laft to Right as you sit on the bike.
Check resistance through the pickups, they can break down. Low battery voltage can also cause some peculiar symptoms, so make sure that's in good order too. Poor earths can also cause problems, but since you have a spark when you switch wires, it probably isn't an earthing issue.

Good luck, keep us posted

[FZ1]

Thanks for the input! So does that mean the diagram I've been looking at is wrong?
http://www.ns400r.co.uk/ns400r/manual/1 ... m/17-0.htm

Cheers

[Mark]

Well, one of us is and it's rarely Honda...

The important point is that he lower two cylinders fire together. So, if you can only get a spark on the top cylinder by using the CDI and/or pickup from the bottom cylinders, then the area to concentrate on is the CDI and pickup for the top cylinder.

[FZ1]

Got the cylinder numbering correct, things make sense now. The diagram was labeled wrong! So now I've got spark on 1 and 3, No spark on #2. The ignition coil will spark (incorrect timing obviously), only if i switch wires on the coil after desoldering the one terminal. Ive plugged the larger CDI for 1 and 3 into the plugs for the #2 cylinder (basically using the #1 pickup and cdi) and no spark. Both pulser coils have the recommended resistance, and arent grounded, as per the test procedure in the manual. I'm going to pull out the CDI's and do those tests tonight. can anyone verify that the larger cdi will fire if plugged into the harness as #2? I wish I had extras to swap parts with but this bike is new to me, and parts are NLA from honda. But i did notice a honda trx400 cdi looks suspiciously like the #2 cdi in our bikes, and is available, and is only like $20

cheers

[FZ1]

*BUMP* can onyone confirm that a 1&3 cdi can be used to test a #2? And what is that little coil thing in with the stator that seems to power the cdi's? Not the pulser coils, but the large barrel connector next to the 3 yellow stator (ac) wires plug and the pulser coils plug. I cant believe the possibility that I have 2 sets of CDI boxes and both of the #2's are dead HELP MEEEEE

[Samuli]

I think that is the exciter coil(s) coupler.
Have you measured them?
In the service manual on the last page of ignition system, there you have the procedure how the test the exciter coils! If they are bad the engine wont run, but its strange that your not getting spark on one cyl..
But measure them just to be sure there in spec.
If theyre out of spec, its a new stator or a rewind to the old one.


Could be some sort of wiring issue? Have you tested your getting power to cdi etc.

[FZ1]

It turns out the previous owner (I bought the bike not running) had plugged in the little pigtail going to the coil from the #2 CDI into the neutral switch connector, and then taped up the bundle!. Thanx to all who tried to help, but the only thing that solved it was a scalpel used to cut apart the harness

[Mark]

Pleased to hear that you've sorted it.

I don't think that any tips or suggestions would have come up with that!

Well done, perseverance can pay off..

I had an "electrical problem" with mine when I fitted a rebuilt motor. Turned out to be crank seals. Not what you would expect on a fresh motor when you'd payed for a rebuilt crank with new seals... Trouble was, I'd just had a programmable ignition system fitted, so weeks were wasted assuming that it was an ignition fault. You live an learn. If it wasn't for Ian Wright and David Reynolds, I'd have thrown the towel in. Thankfully, they didn't..