TOPIC:

I put in the Dyna-S Friday ( thanks Jeff ). Runs nice...at times.
But I still have #1 turning black and # 4 popping.
But it doesn't always do it:angry:
I start it one time, power out the a$$ NO popping.
The next time it pops and backfires from #4 carb and out the pipes. I have replaced plug wires, swapped the wires from #1 to #4. It doesn't follow the wires..
After a 15 hour road trip this weekend with a fellow Kawasaki nut ( I got him hooked thirty years ago ) We had time to talk about Kaws.
I'm wondering about that one coil:dry:
Since both cylinders fire off that coil...( #1& #4 )
Anybody ??




1974 Z1 900 with everything from the block up new/ replaced. Jugs honed, checked, new rings, new cam chain, WG carbs, K&N pods, Dyna 3.0 ohm green coils, Dyna-S ignition, new head & valves, new carb boots, new exhuast gaskets. ALL new!!!

Sounds like #4 is runnng out of gas causing it to be lean. Try flushing the lines to #3 & #4. Take out the drain plugs and catch the gas in something. Take a coffee filter and fit it in a funnel and dump the gas back in the tank. If there is any dirt it will show up on the white filter. Do this several times using the prime position on the petcock until the gas comes out clean. The problem with #1 could be the same thing. Dirt may have the float valve leaking causing the fuel level in the bowl to be too high, which will make it run rich. You may have to clean out the whole fuel delivery system from the hoses to the crossovers between the carbs and also the float valve seats.
Dirt will collect in the bowl and then sometimes be sucked up into the jets causing a loss of power.
Possible you're on the right track with the spark but I would think if it is that it would more than likely be a loose connection in the ignition system.
Good luck. It can be tough tracking down an intermitten miss.

Pat, about the only thing I haven't seen mentioned is compression. Have you checked?

Pat I agree with michikawi. These intermittent things are loose/broken wires or dirty fuel to the carbs.

See that you have aftermarket coils. The Dyna coils are prone to cracking and if cracked will short. You might want to give the 1/4 coil a careful examination for spider cracks on the ends or around the cimcumfrance. If the coil isn't cracked, measure the primary and secondary impedence. You should see 3.8 ohms primary and ~15-20K ohms secondary (between plug wires. The last thing to check is the voltage going to the coil. The popping sounds like either a short in the coil which will show up in cracks or bad impedence readings OR you may have intermittent power going to the coil... in this case, check the non-model specific Filebase for the "coil mod"... I suggest it anyway.

If you can catch the problem when it is occuring, this would be a good time to check power to the 1/4 coil to see if it is down some. Since power comes in from a ONE INTO TWO plastic connector above your valve cover, and seems to only affect one coil, then look at this power wire feeding the 1/4 coil first as a potential source of the problem. A black wire comes off your Dyna pickup (left one as you look at it) and since this is new, shouldn't be the problem. Check power TO the Dyna S as well... it is on the red wire you just hooked up to the coil powering wire. If you used the blue splice they gave you, remove it and solder this connection.

I have already done the "WG" coil wiring upgrade. I will start checking the other things ASAP (as long as the wife is ok with allowing me time to do it)
I checked my timing AGAIN last night with the timing light, backed it off a "touch". Cleaned the new plugs, checked the color of the spark on #1 & #4.( orange/ blue ) Took the wife out for a twenty mile ride and had no problems:S But that's just the nature of this problem.. one time smooth hard running, next time crap:angry:
I have some concerns about my wiring harness... I don't think Kawasaki removed the brown plug on the main wiring harness and wire nutted them together It was a farmers bike before I got it back ..
I was warned that I would be better off buying another bike, than getting this one for free.
So... on the "list" for the Winter is a new wiring harness and a "new/used" main wiring harness plug-in thing.
Pat

Hi Pat, to isolate or eliminate the coils as the culprit, swap the input wires and plug wires to make coil 1/4 now feed 2/3 - see if the problem follows the coil, or stays with the same cylinders

Jeff.Saunders wrote:

Hi Pat, to isolate or eliminate the coils as the culprit, swap the input wires and plug wires to make coil 1/4 now feed 2/3 - see if the problem follows the coil, or stays with the same cylinders

That seems like an easy way of figuring out IF it's that coil.
And that will only take a couple of minutes to check with no tools!!
Thanks, I'll start with that tonight.
Pat

Jeff's suggestion made more sense than mine. I tend to run with the multimeter... I think that if you swap coils 1&4 for 2&3 and see if the problem moves, that makes some sense. If the problem moves, then you will have good reason to start examining the coil carefully both eyeballing and testing w/meter.

FWIW: Mr. Saunders sells replacement wiring harnesses. As far as the junction that the harness plugs into, he may have a nice one lying around as well... I don't think those things are made anymore new in the aftermarket or keep your eyes on eBay...

wiredgeorge wrote:

Jeff's suggestion made more sense than mine. I tend to run with the multimeter... I think that if you swap coils 1&4 for 2&3 and see if the problem moves, that makes some sense. If the problem moves, then you will have good reason to start examining the coil carefully both eyeballing and testing w/meter.

FWIW: Mr. Saunders sells replacement wiring harnesses. As far as the junction that the harness plugs into, he may have a nice one lying around as well... I don't think those things are made anymore new in the aftermarket or keep your eyes on eBay...

I already have my eye on his replacement wiring harness;) And I'm sure I can bug him until I get a nice used main electrical "box". Or watch e-bay long enough for what looks like a nice one..

Along this line... What years interchange on the main electrical "box" of a 1974 Z1A?? PLEASE don't tell me check buykawasaki, or bike bandit, as they don't show bikes that old:angry: All they show are those new fangled modern KZ's from 1976 on..

Post edited by: patmann, at: 2005/10/19 09:26

If you mean fuse assembly in your reference to an electrical box, Kawasaki used the same piece in 56 different models. I show bikes from the KZ 200 A1, 250's, 305's, 400's, 440's, 650's, 750's (twin), 900's and 1000's as having the same fuse assembly. Part # 26004-035 for the 1976 kz 900 A4. 1976 was the earliest listing that I had, but with this much model diversity using the same part I'm sure that whatever you yank off a wreck at a salvage should work.

luvmykaw wrote:

If you mean fuse assembly in your reference to an electrical box, Kawasaki used the same piece in 56 different models. I show bikes from the KZ 200 A1, 250's, 305's, 400's, 440's, 650's, 750's (twin), 900's and 1000's as having the same fuse assembly. Part # 26004-035 for the 1976 kz 900 A4. 1976 was the earliest listing that I had, but with this much model diversity using the same part I'm sure that whatever you yank off a wreck at a salvage should work.

I'm talking about the main electrical area/ battery box. Mine SHOULD[/i]have four plug ins.. the brown one is missing and all the wires that it should have pluged into it are cut and wire nutted together:( . Gee can't think of why I might be having problems..
Thanks for the info, Pat