Dyna III Problems

[MikeW]

I installed a Dyna III system on my LeMans 1000 in December 2015. The original points plate was totally stuffed and nearly all the threads were stripped making it hard to get the timing right for any length of time.

The installation was straightforward and after a bit of adjustment the bike ran well at all engine speeds. After the first week I replaced the original coils when one of them failed. The replacement coils were two 5 ohm aftermarket can type coils.

After many months of trouble free operation I started to get an intermittent rough idle and low rpm hesitation. This either occurred around ten minutes into a ride or after a break during a ride. Typically it would go away during a ride and only surface occasionally if the bike idled for a long period of time.

It was quite hard to catch this problem in the workshop but I did manage to determine that it was the right cylinder that was missing after some effort. First of all I replaced both plugs and plug caps and finally swapped out the right side ignition coil with a spare which seemed to fix the problem for a couple of weeks. However the problem returned but this time seemingly on the left side. At this point I swapped the two ignition coils (left for right) and the fault vanished again for a few days.

Finally, a week ago one side cut out completely and stayed dead for the rest of the ride home.  After the bike cooled down I tested the ignition system with my timing light and found that the left spark was missing. I tried swapping the sensor leads over and the left side remained dead. I then swapped out the left coil with a spare with the same result. I also tried manually triggering the unit with the plugs removed and the left side was definitely dead. During this whole saga I also checked the ignition wiring, connectors and earth.  It was at this point that I emailed Dynatek.

However, the next day before packaging up the unit I thought I'd just confirm everything again and lo and behold there was now a spark on the left side! I did notice though that the left side spark seemed a little erratic and did miss the odd spark here and there though. At this point I swapped the sensors wires and the plug leads over so that the module and coils were reversed. This time the occasional misfire stayed on the left sensor side indicating that the sensor may be at fault and not the module as indicated the day before. Very confusing!

One fault, two faults, or is it me? After this I'm doubting my sanity 

I've now mailed the system to Dynatek for servicing. Hopefully they will find something and it will be covered under warranty.

Mike

[jacksonracingcomau]

. At this point I swapped the sensors wires and the plug leads over so that the module and coils were reversed. This time the occasional misfire stayed on the left sensor side indicating that the sensor may be at fault and not the module as indicated the day before. Very confusing!

One fault, two faults, or is it me? After this I'm doubting my sanity 

I've now mailed the system to Dynatek for servicing. Hopefully they will find something and it will be covered under warranty.

Mike

Note you swapped plug leads, problem went with dicky lead, not a coincidence.
If you didn't send them leads, look and test. I think you'll see "fur " on the end of one, where it wasn't quite making, if not test for continuity.
I think you've proven everything else

[centauro]

Looks like you covered pretty much everything, but just in case you have not done this, take apart and inspect the 4-way Molex block connector to the right handlebar switch.

My '84 SP did pretty much the same, with erratic idle and sparks. I eventually found the white wire in that block (the one going all the way back to feed the coils) had mostly melted due to high resistance in the severely corroded contacts in that block. The wire would overheat because of  the high resistance, and fail to carry the load of the coils. After cooling down, the motor ran fine for awhile until the problem reoccurred.
I replaced the melted wire, but I also sent the Dyna module to Dynatek for testing, and it was actually found dead for one side of the ignition, along with one of the 3 OHM Dyna coil and a defective NGK plug cap. Dyna replaced them at half a price.

I suspect Dyna ignitions and coils only like a solid 12V supply and proper gauge wires. Some members here have installed a dedicated relay to feed them directly from the battery, bypassing the original fuse box; this is on my list to do, as well.

Good luck, and let us know of your progress. I am sure you will fix it soon for good.

[rodekyll]

The common element in the story is you connecting and disconnecting things -- almost always with some effect on the problem.  I'm with him ^.  the problem will be in the wiring -- terminals almost broken off wire ends, brittle wire, bad molex seating, corrosion, etc.

[Kiwi_Roy]

Note you swapped plug leads, problem went with dicky lead, not a coincidence.
If you didn't send them leads, look and test. I think you'll see "fur " on the end of one, where it wasn't quite making, if not test for continuity.
I think you've proven everything else

You can check the leads for continuity by pulling the plug cap and measuring the resistance from cap to chassis
you should get a reading between 5,000 and 8,000, the main thing is both sides should be the same.
This measures the plug cap. the lead and the coil HT winding all in series.

If the leads are the type with carbon core I would throw them out and replace with copper type.

[Chuck in Indiana]

I suspect Dyna ignitions and coils only like a solid 12V supply and proper gauge wires. Some members here have installed a dedicated relay to feed them directly from the battery, bypassing the original fuse box; this is on my list to do, as well.

Yes, I did this on the Aero Lario. I looked at the white wire (kill switch) that feeds the coils and thought, "No." I *like* the Tron switches, so put a relay on it, too, along with lights.
That said, now, I've introduced a failure mode.. a bad relay.. but it certainly has less chance of failing than those little wires and terminals in the switchgear.

[MikeW]

I received a package back from Dynatek a couple of days ago and it contained a new electronics module. My original sensor plate was returned as it had tested ok. It only took around 30 minutes to fit and re-time the ignition and sally forth on a test ride. The bike ran perfectly with a rock solid idle again.

Finally for good measure I again checked the voltage at the coils and there was very little voltage drop and then only at idle.

Thanks to Dynatek for their great after sales service   

During the wait I'd also decided to upgrade my coils to the Dyna 5 ohm coils and they appear to run much cooler than the can type 5 ohm coils I had fitted. The Dyna coils are much larger than the original type and it was a bit of a squeeze getting them to fit. Luckily the side panels have a fair amount of clearance all round.

[pehayes]

Like you I just spent several months chasing an intermittent spark from a Dyna-III setup on my
SPII.  Oddly, plug would spark in the open air but not inside the cylinder.  Coil was that weak.  Had to use an inductive timing light to confirm no sparking with plug installed.  I added the Dyna 5 ohm coils from MGCycle and that cured ALL of my woes.  Nothing wrong with the trigger unit but it seems to work a whole lot better with their own coils.

Patrick Hayes
Fremont CA