Starter

[pete27car8nvo]

As a new starter in the club my first Q is how to start my Douglas Mk4! I can't find an ignition switch anywhere I know it's a magneto system but there is no spark at the plugs. I've found what I assume is the stop button but is there a switch? Thanks

[Dougiethenoo]

The cut out switch earths the points to stop the bike, see wiring diagram attached.
Try removing the cover over the points to eliminate the chance that the magneto cutout switch or broken wires anywhere are earthing the points.
Check the points are opening as the bike is kicked over.

[pete27car8nvo]

Thanks Dougie. I took the mag' cap off and checked the points which seem to open twice per revolution. I assume there's no 'ignition on' switch so just kick start when ready! I checked the HT leads and the spring loaded carbon brushes are fine so can only assume the mag' is faulty!

[eddie]

Have you cleaned the points? If the bike has been laid up for some time, the points will probably have an oxide film on them. Just pull a piece of fine wet and dry paper through the points a couple of times, and check again for a spark.
  Regards,
                 Eddie.

[kev]

  this is one of the best sites for magnetos... http://www.brightsparkmagnetos.com/
  there is a LOT to learn if you want to live comfortably with a lucas magneto...
they can be a total mystery compared to modern systems...almost witchcraft...but once worked out...they will keep sparking into the next century...
  for a start...check the plug gap and point gap...are your plug caps non resistor...wires ..solid copper core??  the points to points plate.. oil...corrosion...??  centre screw contact??  new non resistor plugs
  a spark across a .010 plug gap..is fine ...but needs to jump near 1/4 inch to start a motor...  what I do with a spark plug... is break the earth electrode off...and see if the spark will jump across the gap to the threaded bit..thats nearly  1/4"... needs to do that  to run your engine...you are aware that turning over without a plug in  (both leads) ...will still produce a spark...generally it sparks to earth back at the weakest part of the coil...burning a hole  through most expensive part...   
I have a brightspark condenser in my K2F ...  turned a completely dead magneto into a good reliable one kick starter...and great runner....50 BSA A10...install took maybe 45 minutes start to finish...

folks seem to winge about these lucas things...but all of my cars trucks , bikes  with modern ignitions...and from 7 to 40 years old...all have had most ignition components replaced...  my 50 _80 year old magnetos....sometimes just a good clean....sometimes a condenser

good luck with it
  and pick up a set of B.A. spanners
   or you will be looking for B.A. nuts..  which are even harder to get than B.A. spanners

[Daren W Australia]

Hi If you need BA this guy has it all http://www.classicfasteners.com.au/brass/ Regards Daren

[pete27car8nvo]

Thanks all. Sparky is back after cleaning points but weak. Iv not tried to start the bike yet as carbs some work!