Electronic ignition

 The setup uses a Dyna S single fire electronic ignition but in ClockWise (CW) rotation. This was adapted from the units most commonly for CCW rotating HD cone motors. (Shovel, Evo.)

Setup uses one magnet on rotor with two pickups. Rotor fits a conventional advance unit. Note: be sure to use a CW Pan/early shovel advance unit not from a later cone motor which advance CCW. These Dyna modules work in either direction of rotation unlike some other brands which are mono-directional.

I found a distributor with auto-mechanical advance. It dismantles to the degree to which it's able to be fitted/removed with sufficient clearance to front cylinder head fins.

The aluminum plate which pickups are mounted was lathed down to fit. Cone motors run a slightly bigger diameter plate but I was able to retain the adjustment slots. I carefully centered the plate so rotor-pickup gaps remained within tolerance.

Dyna recommend 5ohm coils for street use. On hand I had 2 x 4.3ohm coils so I used a 0.7ohm ballast resistor to make a combined 5.0ohms. This means less work load for the pickups.

Update: now running Dyna 5ohm coils.

Here is the plate ready to fit. The distributor itself has had a few previous lives and been adapted.

Note: Front and rear pickups are marked in the correct sequence for CW. If these were in a cone motor, those pickups would be reversed. The smaller pickup is fixed with a countersunk screw from underneath. (check tightness!!) Once front pickup timing is set by adjusting with the outer hold down slots of aluminum plate, then the rear cylinder can be checked and adjusted. It's pickup can be adjusted on its' own slots if need be, Dyna say it's set at factory but prudence says check and check again. Use CPU heatsink grease for mounting pickups.

Bare timer base. White mark is for basic timing on front cylinder.

CW advance unit from a Pan/genny-Shovel. Aluminum magnet rotor fitted with smear of  regular grease.

Another view.

Fitted up

Coil pair. Front coil has white trigger wire.

Rear pickup has letters "BL". This is so I know which color wire it uses. Black in this case.

On the rotor there's a white dot where magnet is.

My strobe light. Internal drycell battery powered. The other little item is a screw-in glass window for crankcase. Note it has some black tape forming a tube shape aperture.

I bought a new kit from OEMcycles. Modules are much shorter in height but function is same. Rotor is plastic.

When I transferred the modules on to my existing aluminum plate, I found the taper-seat screw did not tighten so I used a longer screw and nutted it from above with Loctite blue. 

It's thought that should a module fail, bike could still be ridden home on one cylinder. Slow trip though.

Strobe timing tips

Paint the flywheel marks white then detail with black. I degrease 1st with brakekleen and allow to dry before applying paint. My rear cylinder is marked from when I rebuilt. I used the "positive piston stop" method with degree wheel to get accurate readings.

Wrap black tape around glass window as pictured above. This helps improve visibility. 

Aim strobe light at slight angle. This dramatically reduces glare from screw-in glass window. 

Have bike vertical upright (or lean to right). This keeps crankcase oil splash from obscuring vision.

Test run

Future mods contemplated.

Vent holes in distributor cap to help cool pickups. The thought is not to make big holes that allow debris or dust in. Worse could be iron filings as they may stick to the magnet.

A better way of routing the cable from the distributor. It runs close to jug fins so any guard or sheath to help prevent heat damage. Possibly run cable internally though it's tight for room. 

Accidentally leaving ignition on could possibly overheat a module so maybe think about a big, bright  ignition light or oil light in plain view. A buzzer IC would be a nice idea.

Update: A 12v buzzer is fitted and works very well. Good thing engine is an easy starter.

Specifications

Volts: 12v negative ground

Maker/model: Dynatek Dyna S single fire DS6-2

Coils: 2 x 5ohm primary resistance

Rotation: Clockwise (CW)

Spark plugs/gap: Champion N12YC .035"

Plug wires: PVC Copper core

Suppression: None

Rotor to pickup gap: 025" - .040"

Timing: 35°BTDC full advance update: reduced to 34°