Faulty Dyna 'S' ?????

[zed1015]

Have used dyna 'S' ignitions on all my Zeds for years now without any problems but now i've a suspicion that i might have a pickup on the blink.
Bike suddenly started running a bit off about three weeks back, Running rough and spitting back under 2500rpm and not as easy to start (not the usual one kick). Above 2500rpm it still goes like a rocket (Although the higher revs could be masking the problem). Did suspect all the usual, dodgy plug / pilot jets / split carb rubber /sticking ATD etc etc, even re-done the shims ,cam timing and all electrical connections etc, in fact everything i can think of with no effect, I rebuilt the head back in Jan with new guides, seals, recut seats etc and done 1000's of miles since so know it's not a valve not seating or sticking which only leaves the ignition system playing up.
So! Has anyone had their Dyna 'S' give trouble and what were the symptoms ?. Do they usually just pack up altogether or start to break down intermittently ?. Cheer's Zed.

[Big Fluff]

Not heard personally of any Dyna 'S' going up the spout (millions of Dyna 2000's though).

Usually when a pulsar coil breaks down, the breakdown starts when the pulsars get hot. The worse they get, the sooner they give the problem
i.e. First fire up fine, 2 miles the odd splutter, 10 miles down on to 2 cylinders. Then when the pulsar has cooled down sufficiently, it'll be OK again for a short while.

Try running the bike without a points cover on to allow air to cool it and see if the same problem persists.

Will.

[Mark Stratton]

Unfortunately mine went kaput due to regulator / rectifier allowing too much voltage through
Does your have any white goo oozing from the pick - ups? Apparently this is a sure sign of failure due to over voltage.

Now its a new Dyna S and regulator / rectifier for me. Not good when your skint.

[zed1015]

Usually when a pulsar coil breaks down, the breakdown starts when the pulsars get hot. The worse they get, the sooner they give the problem
Will.

Yes, that's my experience. But this problem is from cold. It feels like its missing every other spark on a couple of cylinders till around 2500rpm then it clears. Been through the entire bike, tried my spare carbs while i ultrasonic cleaned its own, comp test gives spot on 150 psi on all cyls from cold. Leak down test was good. resealed the carb rubbers which were new in jan etc etc. Only other alternative will be to splash out and buy another dyna then if no joy pull the top end to see if there's something out of the ordinary going on .

[Mark Stratton]

Forgot to say that mine started running rough throughout the rev range and was a bi*ch to start.
The white goo that oozed from mine was at the bottom of the pick-ups and looked like silicon sealer.

[zed1015]

Unfortunately mine went kaput due to regulator / rectifier allowing too much voltage through
Does your have any white goo oozing from the pick - ups? Apparently this is a sure sign of failure due to over voltage.

Now its a new Dyna S and regulator / rectifier for me. Not good when your skint.

Pick ups are like new and my charging system is perfect. Have been through the entire electrical system already and have ruled out almost everything i can without trying another dyna or pulling the motor apart as a last resort which of course will cost mucho dosh.

[zed1015]

Forgot to say that mine started running rough throughout the rev range and was a bi*ch to start.
The white goo that oozed from mine was at the bottom of the pick-ups and looked like silicon sealer.

Sounds promising. It seems like it's 1 'n' 4 cyls but it's hard to tell as it only spits back on the move. I do have a spare good pick up left from when i threw it down the road a few years ago but didn't want to cut in to the wiring until i was sure. Would be an easy job if it just packed up altogether.

[KWACKERZ1]

Dyna s ignitions are great and normally reliable and its the only thing I would buy to use on a zed.

But they become suspect if they take a knock, If the bike ever gets dropped (pretty common for me when I was racing) they dont seem to like it.

At least once the rotor bit seemed to lose its magnetism and on another occasion I had one of the pickups go faulty.

But thats the only times they have ever played up for me.

[zed1015]

Ok. Had a close look at the pickups and lo and behold when removed from the back plate there was a white sticky residue on the underside. I had a good spare 1-4 pickup so i've swapped that and wiped the other one clean. Instant improvement , Thanks Mark think you've saved me a lot of mucking about. Still not quite right as 2-3 needs replacing but its hardly noticable so i'll have to order a new set unless anyone has a spare 2-3 pickup knocking about. Cheers.

[Pasc]

Won't dynatech replace the unit ? I've always heard good stuff about them when it comes to replacements.

[debben1]

Hello Z1015, There should be white stuff behind the pick ups, this is there to bond the pick up to the back plate, as Mark has already said if it oozes out from behind the pick (soo then becoming visable) it indicates a problem, normally excessive voltage to the pick up. have you checked the springs on the auto advance unit, this would give poor starting as the ignition is too far advanced yet would run fine when above about 3000 rpm, Regards, Steve

[zed1015]

ATD was bought new from you not too long ago and is in tip top nick and now that i've replaced the 1-4 pickup its back to starting first kick. I tested the charging system and it's not kicking out excess voltage so i'll just put it down to old age wear 'n' tear (and yes the white contact paste had just begun to appear from around the edge of the pickups). Not bad really since it's been on the bike virtually untouched for over eight years and it gets hammered nearly everyday. Expect an order for a new dyna 'S' soon

[knut]

you could try and connect a multimeter and read the voltage on the primary of the ht coil (12v side),i,m thinking of doing it on mine cos i suspect something similar is happening to me.by the way i think the white paste is to help heat transfer from the pickups .good luck

[Al]

As was already said; the white paste is supposed to be there.

Its a good check to make sure its between 25 and 40 thou of clearance between the cam and module sensor point.
I used those circular wire gauges which are designed to clean gas nozzels on BOC Saphire guns and the like. The first 10mm is a plain shank and the rest is effectively rasp. Should'nt get into too much trouble if you go easy.
http://www.weldinggear.co.uk/Gas-Consum ... -Cleaners/
Reasons given in the text below.

Six months ago mine was giving me the proper arse.
Took it to bits and examined it all with a microscope.
Found two things.
Someone had or it had happened that the peg on the end of the c/shaft was longer by a tiny amount than it needed to be. The groove on the back or the A&R unit is tapered. The A&R was spinning slightly eccentrically as a result.
Filed a corner off the roll pin and hey presto.
Second; the person who installed the Dyna 'S' had left the thin flat shim between the baseplate and the rotating cam. (about 20mm by 16mm by 5 thou approx shim)
This had a single crack in it making it like a spring washer. This was jamming the A&R rotor from either advancing or retarding depending on how it felt at the time.

Looked like a one-off and then Andy Z1R's bike wouldnt pull 10,500 at Brighton Speed Trials.
Took the points cover off and what was whizzing around in the Dyna 'S' electronic pickups............ the shim. It has a bit missing and that never was found but i thought that a pattern was starting to emerge.

Might be worth a look.

Spoke to Dyna Technical about it and he said he had never seen the shim and it must have been residual from original Kwak set-up for the A&R unit.
I took this to mean that it wasn't needed.







AL

[zed1015]

As far as i can tell the pickups are starting to fail due only to age and since i fitted my spare 1-4 pickup the problem is barely noticable. Like the Drouin project i personally nut and bolt built this bike from the ground up with no outside involvement apart from the powder coating, even down to creating the entire wiring loom from scratch so i know the bike like the back of my hand and there are no nasties lurking from a previous owner. I already did every mechanical /carburation/ voltage and resistance test possible including the one supplied with the Dyna before coming to the conclusion that the Dyna was either faulty or there was some other unusual mechanical fault developing within the motor. So i'll just have to buy a new Dyna and bear in mind the symptoms if it starts playing up in another eight years time.