Hey Terry, rather than getting new rims have you got your originals & an you get them rechromed? One of the things I have noted while sorting out my H1 is that there are a lot of very fussy originality freaks in the triples world and one of the zillions of things they look for is that the rims have the correct date codes for the bike. It'll all help you sell it eventually...
Mark, I found a schematic of the ignition units at last, see attached. Is it any use?
Wow, that explains a LOT about those units, Tim!
They had a history of "turning into Silly Putty under the seat" back in the 1969 era. From that schematic, I can see why: if the battery gets low enough to not let that SCR shut off fully, with the capacitively-generated oneshot that circuit describes, it would simply stay ON after firing - probably at low engine speeds, like idle. This could happen around 10.6 volts, like at idle with the headlight on while someone was fiddling with something in the garage(?). The symptoms I always heard were something like: "I had a low battery and jumped it to my [car, truck, tractor] to start it, then it died while I was putting on my [helmet/jacket/girl-on-the-back] and smoke rolled out from under the seat". The failure description was always similar to that.
The [in]famous GM MOSFET "Transistor Ignition" is/was much like that. The MOSFET can fire generous current loads, but if the backside of the turnoff pulse doesn't fly far enough below 0v (to -3.0 volts on the GM unit) then the MOSFET simply stays ON until it melts. Periodically that circuit makes it reprise , even here, for those trying to make a super-simple 'electronic ignition' for a budget build of some type. The last round thru these forums was on CB500/550 bikes, which guarantees their failure because of its typical low-voltage issues (in the USA, anyway).
Seeing that CDI trigger schematic makes me wonder if the GM HEI engineer who made those owned a Blue Streak at one time?
