Firstly why did CollingsBob CLOSE the previous thread on this discussion? Other threads go on for hundreds of replies! Secondly Ian,, Ken Horner is the Aus Start Engineer that makes wonderful starters for much larger engines than ours,,also an old friend of our engine designer P.E.Irving. The "Irving Vincent" creator, when the "know hows" get on with the "can dos" look what can be achieved.
Ken Target is the "Bright Spark" man, Magnetoman is definitely a smart guy in theory and loses most of us in it,(me anyway) but not mechanically minded as he couldn't get his head round that an ATD did not alter the efficiency of the spark like a manual advance & retard does.
Question, manual mag, is it better to have 100% spark at full retard or full advance ? "OLD HARRY" the "A"Rap is a great starter, up until I got home from the French, messed around with it for a couple of days and sort of fixed it, not happy and had heard of "Bright Spark",checked his website, this guy isn't backwards in coming forwards, and willing to share his knowledge giving special tool descriptions to make it you self, (home made stuff is best) well my kids are !
Monday give him a ring and chat,talked sense! Posted midday. Condition,broken slip ring (I dropped it,but not far,crack),Stripped Tuffnel dynamo drive wheel,windings looked good.
Wednesday had a call from Ken Target, confirmed windings good. New, slip ring. bearings, Tuffnel wheel, re-magnetised and of cause a "Bright Spark" Condenser under the contact breaker unit. Received Saturday morning and fitted ready to take her indoors for a ride on Sunday, to date 1300 miles Cost a little over the £100, if a rewind was necessary be over £200, but still less than a third of what a new type BT-H, one of which failed me after salted roads had caused tracking on the LT side of all those fine wires to the coils, try finding out how those things work !? relayed home. Another relay home was also electronic ignition failure on an early Grosset system after the Irish in 2007, now upgraded and working well (but carry a spare trigger unit) not a big item. That is the total road failures in over 400k only because I took off my Scintilla to use else where and that did 200k with out stripping since buying it for £15 from Roger Slater in mid sixties and used since to Tory Canyon went aground off Cornwall as I was working in the I.C.E.shop H.M.D.Devonport.
The beauty with the Scintilla was it could easily be switched from mag to coil ignition as we first did it in 1988 as it interfered with the intercom 1990 went to twin plugged heads but points needed dressing every 2 to 3 k miles. Ostend ferry heading for Bremerhaven, battery flat, pushed off ferry loaded as usual, half an hour back to single pugs mag, carry on.
Now what we did as teenagers & intend doing again as it's cheaper and interesting, my mate Tim had a Tri-Bsa with a bad mag, Johnson / Evenrude out board engine coils ? Mag stripped, took end caps off the armature, hacked off the windings, cut the former in half through the small section, square hole in coil was larger than the core so we put steel shim and the hacksaw fillings (with Aradite) back where we had cut it, replaced the end caps, HT outlet from coil was offset from slip ring, so we married them up the best we could putting a short length copper wire into slip ring segment, rapped tape round as a cradle and filled with more Araldite, ( he had to borrow a Vincent that night) next evening it was hard, so we tried to fit it, plastic edges of coil had to be filed off to same diameter of armature, boxed up and spun freely, baker-light points end cap with cut out in with the bowed leaf spring and carbon contact type used and the regular condenser fitted through that worked very well indeed, but there was a problem, the carbon contact to the points centre screw where the LT passed use to get glazed and a rub with a piece of emery cloth restored it after 2 to 3 hundred miles, one day off the road and he was back in business, cost not a lot for an old OMC spare part and beautifully encased in plastic.
The answer is use some thing we under stand or know how to fix easily, It would cost me more to ride a modern bike than use the one I have and if any thing goes wrong what can one do, use your mobile !