Coil wiring

[robinjo]

OK guys I need your help with electrical stuff...:?

I am having trouble with my ignition, sometimes one coil stops firing, and not allways the same one at that. First I replaced the stock points ignition with a Dyna S whick made it run nicer but the problem still occured, I then replaced the tired old coils with green Dyna 3 Ohm coils which made it run that little bit better still.:-D but the trouble still persisted.

but the problem has worsened lately, now after about 5 miles, more or less it depends on the ambient temperature too, one coil still fails. If I read the wiring diagram correctly the schematic is pretty simple:

1: One side of both coils gets a continuous 12 feed switched by the ignition being turned on through the orange/white wire, this splits up in two after the ignition fuse.

2: The other side of both coils gets earthed by either the white wire or the black/yellow one, the timing of this is controlled by the ignition rotor on the crankshaft.

By replacing the ignition I have new wiring upto under the seat where white and yellow/black hook up with the corresponding colours in the stock wiring loom, the red Dyna wire goes onto the orange/white.

So the problem should be in this area right?

[BadBillyB]

Sounds like the problem might be in the 12 volt feed to the coils. Try "Hot Wiring" it.....Run a fused jumper wire direct from the battery B+ to the coils orange/white wire and take it out for a ride. If the problem is or isn't gone, it will narrow down the possible causes........BadBillyB

[earlfor]

I had that same kind of problem on my 750. My problem was fluctuating low voltage on the ignition wiring. My solution............... The wiring harness connector/plug for the ignition switch is a (If I remember) six wire plug. One of the output wires from the plug (after power has passed through the ignition switch) is orange or brown (cant remember). That wire is supplied by the main fuse and not the ignition fuse. I added a jumper to that wire and and a Y connection to power the + side of both coils. I also connected my red Dyna s power supply wire to it. I capped off the original coil supply wires in the wiring harness. The problem never happed again. :-)

Earl

[robinjo]

Both very helpfull suggestions!

Even though I mentioned that the positive side was switched on by the ignition, in my mind the power wire only did a tour from the battery to the ignition fuse but the contact switch is also in the 'loop' expanding the area for a faulty wire or connection.

I will use the hotwire trick first, for a more permanent solution if it is indeed the problem what exactly is a 'jumper' ? Is it a take-off like supplied with the Dyna ignition that you use to connect the red to the orange/white?

[BadBillyB]

Both very helpfull suggestions!

what exactly is a 'jumper' ? Is it a take-off like supplied with the Dyna ignition that you use to connect the red to the orange/white?

A jumper wire like I am referring to, is just a spare piece of wire you have laying around that you modify yourself to suit the situation. Like an alligator clip to the battery, followed by an inline fuse (10amp) and then a run of wire that will reach your coil connectors.....The term "bypass wire" would have been a better choice I guess......This will eliminate all the wiring harness connections and switches.....BadBillyB

[robinjo]

Allright thank you, I have rigged up said system and took a testdrive, still one coil failing after a few miles... Got home, measured and there still was 12V to the coil (Duh) no continuity on the earth wire but that should only happen once every crankcase revolution right? Need to get someone else turning the motor over to chekc that one... I then measured the resistance of the non-firing Dyna coil.

Primary 3.6 Ohm
Secondary 14.65 K.Ohm without wires and caps.

Sounds right doesn't it?

so maybe it's the connection of the spark wires? They are Dyna wires that have a clamp on them that you press right in the coil, if one of them has a bad connection would that cause both not to fire? Or is it more likely that the coil itself is faulty?

Looking forward to your advise, too bad I am gone for the weekend, good thing I have a bike that works too!:-D

[BadBillyB]

What method are you using to determine that one coil in not firing anymore.....BadBillyB

[robinjo]

What method are you using to determine that one coil in not firing anymore.....BadBillyB

Exhaust pipe temperature and checking with a spare plug.

[robinjo]

I fitted one of the coils from my Katana, still have the hotwire system on, ran it for 2 miles still have the same symptoms.

So I think it's my ignition itself that is playing up.:?

[Carter Turk]

I had a similar problem with my Dyna S. After about 5 miles like you said it started to cut out. The 1-4 trigger on the Dyna plate was at fault. I sent it back, as I only had it on 2 months before it failed. They replaced it no charge.

I followed Earls advice to run the RR directly to the battery to eliminate the lighting loop, but wired the Dyna S into my old wiring harness's Org/Wh wire.

I'm not electrically inclined, but thought the whole time it was a bad coil.

[robinjo]

I had a similar problem with my Dyna S. After about 5 miles like you said it started to cut out. The 1-4 trigger on the Dyna plate was at fault. I sent it back, as I only had it on 2 months before it failed. They replaced it no charge.

I followed Earls advice to run the RR directly to the battery to eliminate the lighting loop, but wired the Dyna S into my old wiring harness's Org/Wh wire.

I'm not electrically inclined, but thought the whole time it was a bad coil.

And it turns out it was indeed the Dyna ignition that was at fault, I swapped it with another one I had laying around and it runs flawlessly again.\\/

Thanks to everyone, couldn't have done it without you guys!