Random idle misfire after rebuild

Your help is veru much appreciated.
Yes, i test ed my coil , cold or hot they show the same readings..
Who know something about that magnet i mentioned above? The only thing i know is that when a magnet is broken, it change his polarity.. But i cant understand what can happen in the pickup coil system..
This thing is terribile, i literally hate this random issue , occasionally it happen and make me want to hit the 550 with a hammer..

Do you have a timing light. Connect it and watch the flashes on each wire. You should see the miss. I suspect coils.
Steve

swest wrote: Do you have a timing light. Connect it and watch the flashes on each wire. You should see the miss. I suspect coils.
Steve

or worn springs, pins or cam to shaft clearances in the advance mechanism.

I've watched the light while switching the wires. Some would flash steadily and one would show the miss. I'd look more closely at that HT wire. Found lots of bad connections that way.
Steve

pete greek1 wrote:

650ed wrote: You may want to try this...

When the engine is still cold and running with no misfires use a hair dryer or other tool to warm up one of the coils. If the engine then misfires, that coil is suspect. If not, heat up the other coil to see if that causes the misfire. Ed

Ed, he said he did that in his 1st. post,
Pete

No, he didn't. he said:

I tested my ignition coils with a hairdryier and i have always 3ohm primary and 12.90 ohm secondari

You can hairdryer a coil with an ohm meter until hell freezes over. It won't detect the typical failure mode which is high voltage arcing over. There are HV coil test instruments but an Ohm meter is pretty much useless unless you are seeing a dead short.

I think the "idle cold" and shoot with a heater is a good idea to find a bad coil. If there is a timing light attached, you should see the miss.

i think the advancer is lubed and properly installed. the springs are ok, it returns all close.
today i tried another set of coils zc006 tr12v, the same of my gpz. (i don't know if those coils where good or not)
worst. :dry:
so i put again mine coils, better.
so i found anothere pulser plate and just did the swap. the bike seems to run better....(this pulser also have a crack on the magnet but i'm confident no one dismantled it, so i think the magnet can be upside down or something like that.
anyway i think im in need of a replica new fresh pair of ignition coils..
the darlington igniter i have, show the same measurement of another i tried some days ago, so things appear to be the same.

i just tried a small ride, the bike run VERY smoothly in every condition,( even with pod!) unless she is hot , in neutral, on the stand at idle..at this point i have the random ''tump'' :sick: (anyway bike always keep running, never stalls)
since the idle problem is ''random'' i think can't be a magnet problem, or a igniter problem.
i think the thruth is in the coils. in the next day i will order a new pair and i will let you know what happen. at all they are 33 years old

other ideas? :dry:

I had a timing light.. Inductive type, right? Seems really i miss some flashes !
How to determine if it is coils or IC igniter?

Cut 1/4" off each end and put them back in, check again.
Steve

Sorry swest, idont understand what you are refferring about ? If you talk about spark plug wires, they are brand new.

Moisture can get in the caps or where they connect and cause corrosion. It happened to me. I washed the bike and rode 100 miles to my daughter's place. 1/2 way there it would cut out then come back then cut out again. By the time I got there I was running on 3 cylinders. Threw in a spare set I had with me and rode home. I looked at the old wires and one had green crap in the end of the wire. Snipped it off and put them back on. FIXED I bought a pair of 3 OHM Dynas a month later. Now I have TWO spare sets. :woohoo:
Steve

You are right, but my caps are brand new, and no resistors wires also.
Today i ordered a pair of brand new replica ignition coils. I did the entire engine..so the cooked 33 years old coils have to be replaced in anycase i think.
I will let you know what happen.
My feel is , apart of the idle random miss, a strange sense of "no power" in the 1500/2500 rpm range, and i think this is tired coils.
Since i have compression, and carbs are OK.. I wonder if very old and abused coils can provide alot of problems Like those i have

Have you looked at the advance mechanism? I had a weak pair of springs in mine and the timing marks with a strobe light would dance around at idle to low 2000rpm speeds.
When I took it out and inspected it on my work bench I could clearly see one spring did not even fit in between the two pins, being without any tension!!
It's hard to find the springs but even a little twisting of the loop was enough to tighten that up and my dancing timing marks were much improved.
Also the cam itself can be sloppy on the shaft causing a low speed burble misfire.
That's much harder to fix of course.