The ” Scott is born” project is coming on apace and is now running, but not on my one off electronic ignition system,as I could not kick it fast enough to get a spark, so I took a step back and fitted the coil ignition system, so that I could sort out the mixture and oil levels and sort out the electronics later. When I stripped the distributor to check it out, as you do, I noticed that the mounting plate for the auto advance was stamped 25 degrees, are they all like this? or have I got an oddball? It does not matter too much at the moment as I have to run in a brand new engine and wont be revving too much for a while, but everything I have read says 34 degrees of advance. Dave Herbert.
I’m not sure about the auto advance, I’ve only ever had experience of a DKX2 running at half engine speed, but that was 12 degrees advance, but due to the gearing gave an effective 24 deg. It was awful as it over advanced so I went back to a magneto.
I’ve made/designed many electronic ignitions mainly for model aircraft use and your comment about not kicking it enough. I’ve always used hall effect sensors and mangnets as the pickup, which work at almost zero engine speed. What kinkd of system have you designed?
There seems to be 8 different models of the Lucas DKX distributor. I have a Lucas manual, plus some swedish add to it, I will try to send it directly to Dave, and to Steven Enticott.
One more reply, if you start out with 9 dg advance at “stand still”, and add 25 dg at full, you end up with your 34 dg
Richard, the electronic system I devised, I wont say designed, as I am not that clever, uses components made by Electrotech in Reading. The stator plate with the pick ups had the three holes on the same PCD as the standard Lucus alternator, so with so machining and juggling, I mounted inside a Brum Scott alternator housing. The twin coils and electronic gizmos that supply the advance are remotely mounted on the frame.
With the plugs removed I can spin the motor fast enough to get sparks, but not with the plugs in, as I can only get one revolution, ie two TDCs.
As it is a self contained unit, I can remove it and run it up on my two speed drill. At low speed which is stated as 400 rpm I get nothing, but at a higher speed, maybe 500 or so, it works. I have been in (frequent) touch with Electrotech, and the main man there cannot understand this as he has used the same set up on T500 Suzuki two stroke twins. He has a plan B up his sleeve so I will be seeing him at Stafford show next month.
The reason I went to the trouble of the electronic ignition, when I allready had the distributor and the alternator was tat I have built the Scott Is Born project as a pseudo 1930s Scott, and did no want the distributor, too modern and too ugly, also, if you have never had one of these alternators in your hand and tried to rotate it, the magnetic drag is very high and must soak up a lot of power, and I felt I did not want this just to run the ignition as I have not fitted any lights.
Iwillkeep you all posted on developements.
Jan, thanks for the Lucas info sheets Ihavnt had time to study them yet
How do you set the Lucas distributor and the points?
I set the points to 0.012″ and have them just fully open at TDC. That’s good enough to get the engine running. Then with the distributor clamp just tight enough to prevent the distributor housing from rotating on it’s own, I take the bike for a run and reach down and rotate the distributor to a position where the engine feels really responsive and pulls well at all speeds. I then stop and tighten up the clamp.
It works for me!
good , that’s what I pretty much did, however the distributor, runs out of room to turn clockwise , hitting the engine case, I thought maybe I’ll pull it and set it back a couple of teeth back and try again .
One tooth should be enough!
@dave bushell wrote:
One tooth should be enough!
one tooth seems to be too much, I had to basically put it back where it was or I would have had too much movement the other way. Looks like I need to pull the cam off the spindle and move that? Its a lucas
Did you turn it the right way?
either way it seems to be too much
Try turning the cam-shaft 180 degrees when replacing it.