Can someone tell me if the two little springs in the mechanical ignition advance unit in the '61 ES2 (it has coil ignition) should be identical?
The unit I received with the bike has two identical springs.
I have a description (off the internet) which states that there should be a stronger and a weaker spring with the stronger somewhat loose on its pins so that the weaker operates first - up to about 1400 (engine) rpm before the stronger spring engages.
I see no comment in the Lucas website about this, nor about any new springs on offer.
Any help anyone?
(Have a better New Year than 2020!!)
Mine are both the same. I can't believe the design is sophisticated enough to need a twin rated spring, and anything left loose ends up wearing things out. I await any other ideas!
I do have a dim memory of there being 2 different springs .
is attached detailing all the technology of spark advance. (Year 2002)
A little long, but main points are in the first few pages. Explains a lot.
But David may be right, were 1960s engines this sophisticated?
Should the ES2 have different springs?
Here it is
Going back some 50 years , I was running a supercharged 998cc Frogeye Healey, and was suffering crank and half shaft breakages,with pre-ignition knocking . I had to play with the advance unit soften things down so it would get me to work across London. More recently I have modified a Ducati unit to give a wider range on a semi race motor to allow starting without kickback. Lots of patience needed .New springs a good idea or at least ensure the spring with least slack pulls the unit back to allow a slow tickover. The Distributor Doctor may have springs.
It would make sense to have two differing sets of springs. One set for a Magneto A/R unit and another for a Distributor 18/D2 sparky thing set-up.
.. for your comments.
Distributor Doctor inform me that the springs for the ES2 are in fact identical.
As a matter of fact, the distributor for the single is the 18D1, for the twin is 18D2.