multiple ignition questions

Im going through the ingition system and testing and resetting everything I can. I tested the coils which checked out ok without the plug caps off for both primary and secondary. it was 4.3 for primary and 14 somthing for secondary.
One cap was an ngk and the other three were stock? The ngk gave me a reading of 5k and nothing for the other three. kind of wierd. So it was hard to tell if i would get 23 ohms across the whole secondary. I am getting spark and firing on all cylinders.
Also i set the points gap even though they are pitted(ordered new ones) and practiced my static and strobe timing. Worked out pretty well but i noticed with the stroboscopic timer that i was getting an inconsistend strobe on 2/3.
I also tested my power going to the coils which checked out at 11 volts with the ignition on.

So here are my questions
1. Can a plug cap still be good even if it does not get a resistance reading at all?

2. Can my coils be bad even though they look fine and test out ok with a voltmeter?

3. Would the intermittent strobe on the timing light be a symptom of the shot points or a problem with the coils.

4. newbie question. How do i know if i have weak spark? My plugs are sooty no mater how much air i give the idle screws. I sparked them against the engine but i dont know how to analyze what i am seeing.

5. how do i explain to my wife why i keep spending money on this bike and it still does not run the way i want it to? Well lets not go there.

i have also posted on the carbs forum "idle frustration" so you know my background.



Thanks Everybody.

1. Yes, most likely those are 'non-resistor' type plug caps.

2. Most likely they are good if your ohm readings are testing OK. There is a chance of intermittent issues, but is rather rare if the cases look good.

3. Not quite sure on that one...I'll let someone else answer here.

4. Weak spark will show as yellow and inconsistent fire when grounding the plug against the block and turning the engine over. Good spark should be big, fat, and blue. Best to check this in a darker area if possible.

5. The wife thing is tough...I better not go there either. :whistle:

Good luck.

Post edited by: savedrider, at: 2006/02/06 22:49

I posted this last year and you can find it in the archives kzrider.com/forum/viewthread.php?tid=26782

If you are getting no resistance reading in the plug cap you can still get a spark but I have my doubts as to the quality of that spark. I would invest the few $ needed in new plug caps. Worked for me.

Your coils sound fine but 11 volts is probably not enough. Look for the wiredgeorge coil mod in the filebase - I think. The low voltage plus old plug caps may be the cause of your intermittent problem,,,,or maybe not but I would think you should fix this before going further.

.......................................................
Woodstock ON Canada
1980 kz750E1, 4->1, K&N pods

#5 tell her you know me,she will understand!:whistle:

On the Z1/Z900 forum there is a post discussing eratic strobe timing and it was found to be weak springs on the advance assembly. Might want to check that. Roy

If 1/4 is consistent, but 2/3 is erratic, I would suspect points or wiring or even condenser. Springs would affect both sets of cylinders.

thanks for all of your responses.

Im going to give the coil powering mod a shot this weekend. I tested my battery at the terminals and it was 12.3v. The reading at the coil was 11v. If the coil mod gets me to 12.3 should i expect a signigicant change in spark? The new points are in the mail. i cant wait to see the difference. I will also pick up some new plug caps at the local shop and give that a shot. If the points replacement and timing does not change the intermittent strobe on 2-3 i might try a spare coil that i have. I have already tried a spare clean advance so i dont think my problem is related to the advance. wish me luck!

Aren't the resistor caps supposed to surpress noise so not to make radio interference and such? Seems to me that no resistance would mean the spark would likely be stronger through those caps showing no resistance.

Maybe my "logic" is way off here, but it seems logical to me!

No reading or no resistance means open circuit which made wonder last year why I was getting a spark at all.

Low resistance would be better.

.......................................................
Woodstock ON Canada
1980 kz750E1, 4->1, K&N pods

1. You get a stronger spark with plug caps that have no resistance.
2. Plug caps with no resistance have been claimed to interfere with aftermarket electronic ignitions.
3. Plug caps with resistance were devloped to eliminate the noise picked up by an AM Radio.
4. Plug caps with resistance lengthen the duration of the spark and give a better chance at igniting a poor fuel / air mixture.
5. Plug caps with no resistance were suposed to scramble radar guns used by the cops in the 60's

I run plug caps with no resistance and have no ignition problems uing a stock 81 KZ-1000 electronic ignition.

Spock

Thinking about this, you say you have intermittent strobe when timing the bike on 2/3... to use the timing light, you need to clip your inductive pickup over a plug wire... such as the #3 wire which is typical since it is a lot more accessible from the points side of the bike. I suggest you try clipping to the #2 plug wire as well. I am suspcious about your wires and caps and would change those and get rid of the resistor plug caps and go non-resistor. If you aren't using resistor type plugs, I suspect that would contribute to this problem. By swapping to the #2 pickup, you could potentially do some problem isolation... Just get a new set of Dyna wires and some new NGK non-resistor type plugs... for a Z1/KZ900 and most KZ1000 applications that would be a B8ES plug. DON'T USE a BR8ES as that is a resistor type (hope I got the R in the right place)...

i put the old caps back on which had no resistance when i measured them as compared to the one NGK cap that i have that reads 5ohms. I tested the spark against the case with the same plug and wire and all caps seemed to preform the same. I did find out that a couple of my "plugs" are preforming less than ideal so i am off to the store again. the plugs i am using are b7es.

Question for Wired George. given that i tested 11V at the hot wire connection to the coils before the relay modification (ignition on bike not running) will the extra 1 volt that i would get from doing the modification make that much of a difference in spark? Gargantuchet suggested jumping a hot wire strait from the battery just to see if it helped before i go through with the modification. Id like to know if others have found that 1volt to make a big difference. Thanks.