2/3 Coil only fires half the time!!! RESOLVED :)

Hey guys,

This happened the other day. I was riding my 82 kz 750 e and it was running fine. I took a break and went back out later and it was kind of hesitant (at constant rpm) as if it were running out of gas. While running today, I pulled off the #1 plug wire, and she stalled out. Did the same for #4, and no change at all...just kept running like I hadn't done anything. I pulled the spark plug, and checked connection to coils, etc. and everything seemed fine. Should I check the points? Would that only affect 1 specific cylinder?

Also, I'm thinking of upgrading coils, and plug wires while I'm fixing the issue. What ohm coils do I want (in the future, I will be making this a track bike)? Do I want suppression wires or copper core wires?

Thanks in advance,

Clutch

And can I run Dyna s ignition with my stock coils (if they are not the issue)?

Everything seemed fine?

Did you rest the connected plug on the head and check for spark? Or just give a look for damage or tampering?

The problem you described could likely be carb related (why would only one of two wires quit?).

Try switching the #1 and #4 plug wires to see if the non-firing cylinder changes as well. If the same cylinder is not firing, then rule out spark. Try switching the plug out for a known firing one. It might be a fouled plug.

How is the battery charge? Is the plug fouled, white, sooty black, or tan? Did you run really low on gas and suck some crap into the system?

Edit; Yes, you can run the stock coils.

I'm certain it is NOT a carb/fuel issue. The exhaust smells like pure gasoline (really rich), which tells me its a spark/electrical issue. I will check to see if the plug gets a spark (just to be sure), and I already swapped out a brand new plug for the old one to check that with no change.

Ok, so I just tested for spark. There is spark on number 4. It seems intermittent to me though. The bike runs smoother with the #4 plug wire OFF! I guess it COULD BE carb/gas issue, however I do have an inline filter, so I'm not sure how that would only affect one cylinder, and not sure what would cause the carb to malfunction other than that seeing as how I changed nothing recently on the bike. Any thoughts on that?

If you are 100% sure that there is good spark at #1 and intermittent spark at #4, then you could have a bad secondary wire. If yours screw into the coil, then they are easy to replace, otherwise, a new coil may be in order. Yes, some folks have successfully spliced a new wire on, but that is not always possible, depending on where the problem is.

If you just want to replace coils or wires, contact Z1E. If you want the whole Dyna system, Dyna's website can set you on the path to strong, if not cheap, fire.

TexasKZ wrote: bad secondary wire

Would this be the spark plug wire, or the wire that goes from the points to the coil?

Secondary wire = plug wire.

That was why I sugessted you switch the 1 and 4 plug wires to see if the possible bad plug wire causes the intermittent spark. If it is the secondary/plug wire then the issue would switch cylinders with the plug wire switch. Mine are long enough to do it I hope that yours are long enough to do it as well. This test would tell you a lot.

If something got by the inline fuel filter then it could get into one of the carbs and cause an issue (inline fuel filters are not perfect. I had two in a row that allowed rust "dust" to pass and foul my passages. I now have my first Kreem lined fuel tank...) For instance, something could be lodged in the float bowl valve causing your #4 carb to flood constantly. It could be a faulty/float bowl valve that was on its way out and chose that time to go bad.

I would find a way to switch coils 1 & 4 with 2 & 3 or switch plug wires 1 with 4 to see if the problem stays with the cylinder or switches to follow that specific secondary/plug wire.

ok...i feel like an idiot now. i think i misread half your first post. btw, battery charge is good...didn't even see that question. i will try swapping the plug wires around (will most likely have to swap between coils as #4 is short) and see what that does to it. thanks for the ideas

I just hope you get it running strong soon !!:side:

And now I am curious what is going on with it.

Your bike left the factory with electronic ignition, not points, and the stock Kawasaki ignition is much better than the Dyna S.

We've covered the wasted spark ignition system on these bikes numerous times, so anyone that does not understand what it is and how it works should do a search for "wasted spark".

Point is, you pull the spark plug wire off a single cylinder, and do not ground that plug wire, you kill two cylinders, like 1&4 or 2&3. If you don't have spark on one cylinder of a pair, then you don't have spark on the other cylinder either.

It's all explained in the manual for each bike model.


You can however lose a cylinder, like flooding out the plug on one cylinder will still leave the other cylinder sparking, as in "Strong smell of gas at the exhaust". Piece of gunk could have broken lose inside the fuel line after the filter and be holding the float valve open (as an example).

steell wrote: If you don't have spark on one cylinder of a pair, then you don't have spark on the other cylinder either.

If this is true, shouldn't there be a noticeable difference pulling the #4 plug? When I pulled that wire, the bike ran more smoothly, not as if I had lost 2 cylinders, instead of just 1.

EDIT: Or maybe I'm mistaken, and It's actually #1 that's not firing, and the reason I notice the difference pulling #1 is because I'm killing #4 at the same time?