When I contacted Price about 6-8 months ago he had stopped doing distributor work.
Jon Hodges spring dimensions look very similar to two Scott distributors I have. I’ve always been puzzled by the odd springs, one relatively light but the other a very heavy wire. The heavy one is out of contact with its pins at rest so can only come into play after a certain advance and then it must dominate the advance control thereafter. I asked Price if he could explain this to me and he said “Ask Mr Lucas!” I have tested the advance curve with a strobe ( but no rev counter ) and as far as I could tell it goes to maximum advance of about 12 degrees as soon as the throttle is opened beyond idle. It was also quite unsteady as commented by Brian Marshall. The advance curves of alanw1947 ‘s distributor, before and after overhaul by Distributor Doctor, are revealing as “before” – 13 degrees advance from less than 1000rpm and completely flat thereafter confirms my own approximate observation – “after” shows a progressive advance up to 19.5 degrees at 4500rpm.
Brian observes that the longstroke engine is relatively insensitive to advance/retard and functions well on a fixed setting, but you have to accept that it will four-stroke merrily at idle. That may not bother you. Several owners of coil ignition models from the distant past have enthused about the very smooth idling and light throttle running to be had by retarding the ignition by 20 degrees or more. This was achieved by lever control of the distributor body – and usually retaining the auto-advance feature as well. Sam Pearce used a twistgrip control on the left side of the handlebar giving 20 degrees ( plus 12 -13 deg auto ?) Roger Wheeler ditto with a handlever – Technicalities 5.3.01 Connell in the 40’s on the Victor Scott used even more for very slow steady tickover. My ex-Lofty Avis 49er with lever control confirms this finding – four-stroking can be just about eliminated. You may find a bit of trouble with engine overheating at the more extreme retard level as the poor combustion efficiency requires more throttle. Its the extra fuel going in that extends the two-stroking range but it also heats the pistons up. So, moderation is probably advisable.
