Coil failed & Dyna s failed

[zapo]

I recently brought a Z1B.
Previous owner had restored it so all new parts and he said he had done about 140 miles.
Seemed fine on a 2 mile test drive.
Two days later it was delivered.

Sorry for the length of this next bit.......

I went about 10 miles to road test it properly and pulled over to check for any problems. All good, press starter button and nothing. Flat battery. Started on the kick start and rode home to investigate.
Multimeter said battery was not charging ( no shit!).
Found that the combined Reg/rectifier was earthed to the battery box and not grounding well.
After earthing it properly The battery was then getting proper charge.
Rode about 6 miles and battery was charging.
Two days later battery still charged and started first time. Went for 60 mile round trip and all good.
Seven days later battery still charged - went for a ride, running great, stopped for a coffee break. Bike restarted fine but after a quarter mile it went very poorly, only running on 1&4. Limped home to investigate.
Battery okay and charging. No sparks to 2&3.
Swapped plugs/ coil wires etc etc
Coil (standard coil) for 2&3 not working.
Dyna ignition module for 2&3 also not working.

And finally to my question - does the Reg/rec earthing fault and subsequent flat battery sound like enough to wreck the coil and Dyna?

New parts ordered but I don't want a repeat episode.
Ironically I've always stayed with points with my bikes as I am a dynaphobe.

Cheers

[Al]

Dyna 'S' is / was very sensitive to overcharging and i guess by implication; spikes / fluctuations in voltage. What date codes are on the coils and the Dyna 'S'? Normally short code like 4/17 8/95 etc. Dyna will be stamped (inked) on the base plate, possibly on the reverse side.
If the Dyna 'S' is more than ten / fifteen or so years old, then i'm afraid youve probably had (someone has had) their moneys worth from it.
If its only a few years old it may have been one of the batch that were faulty that were sent to the UK.
If the Dyna 'S' is new i would suspect the internal short in the coil killed it.
Did you measure the voltage at the battery when running and at the coils too. In order to show that there is no over charging you will need a multimeter on the battery and rev it to over about 4,000 RPM!
Measure between the red wire that feeds the Dyna 'S' modules and earth with the revs above 4,000 as well
AL

[zapo]

Hi Al,
The dyna and the reg/rec and the coils were all purchased new in 2021 by previous owner and presumably fitted as and when he got to that part of the restoration.
In terms of mileage they have all done about 140 miles by PO and about the same by me before the problems started.
I didn't write the charging voltages down but from memory it was 13 point something at the battery at 3.5k revs. I didn't check at coil.

See photo for dyna date stamp.

[KeithZ1R]

what do the pickups look like out of interest, just to gauge how catastrophic the failure was

[Al]

This may be of interest to you.
viewtopic.php?f=4&t=49735

If that was bought new 2021 i'd say that date code is manufactered 43rd week of 2020.
They have changed somewhat since i last had one ten years ago. It was dated 1995 so did a good few years work and then i gave it to someone and it was still OK!
That is the newer version of pickups which potentially puts it in the range (very vaguely) of the faulty batch. Not that thats likely to be any consolation as they will probably say its out of time. I would still phone them and explain though. They still appear to be offering the 15% discount which may ease the pain a little.
As to the cause; assuming the coils are 3 ohms, i'm inclined to think it was a coil failure first and that may be related to the un-conventional earthing issue.
AL

[zapo]

what do the pickups look like out of interest, just to gauge how catastrophic the failure was

Both pickups look Okay (to me anyway).

[Al]

That centre rotor has had a spanner against it, a lot! More importantly; it looks like it has been rubbing against the pickups or one of them at least!!!
AL

[zapo]

That centre rotor has had a spanner against it, a lot! More importantly; it looks like it has been rubbing against the pickups or one of them at least!!!
AL

The marks on the rotor are unavoidable- from my spanner rotating the engine to check valve clearances as I start to wonder what else might be set incorrectly (new bike paranoia syndrome ).
There are no signs of anything rubbing against the pickups and no witness marks on pickups or rotor.

Still waiting for new bits to arrive.
Today I thought I would static check the timing out of interest with the Dyna in its original position.
According to Dyna timing instructions, 1/4 cylinders, left hand Dyna module, with rotor held fully clockwise and bulb connected to coil trigger wire (+ earth) then the bulb should light up when the timing mark on engine is aligned with the small mark on the ret/advance unit (the mark about half an inch to the right of the "F" mark).
This was not the case. When the bulb lit up the actual "F" mark was aligned?
So that is wrong then? (Although engine was running strong before the coil/dyna packed up?).
The 2/3 side is dead so couldn't check owt with that.

[Al]

The marks on the rotor are unavoidable- from my spanner rotating the engine to check valve clearances

Its just my ham fisted way of saying that because mine looked like this, i assumed that they all did. Now i know better.

washer.jpg (33.22 KiB) Viewed 4673 times

https://cdn.ecommercedns.uk/files/2/221 ... l400-7.jpg

AL

[zapo]

Just a quick update to end this thread.
I converted bike to points and all is okay - so far
I couldn't bring myself to go with the witchcraft of electronic ignition and be worrying about another bad experience.
I mentioned before that I like points as you know where you are with them.
Each to his own I guess.

[Bill P]

Glad she's sorted mate