... makes us stronger...
Dang it, another breakdown on the old Sporty. This time ignition related. I've been running an electronic pickup "points replacement" type system that retains the stock mechanical advance mechanism (similar to the popular Pertonix units we run in our older points fired distributors). Well, the advance mechanism has two known points of failure, which usually happen together. The only question is which one fails first, thereby causing the other.
Here is the advance mechanism, your typical flyweights and springs, along with a good retention screw and a failed, sheared off retention screw. You can see how light and inadequate that screw appears:
Here is the back side of the flyweight mechanism. If you look real close, you can see just a little nubbin of a roll pin peeking through one side of the bore. This engages a slot machined into the end of the forward cylinder intake camshaft, and drives the flyweight mechanism. It is also apparent, under the most cursory inspection, that this stupid little nubbin is probably inadequate to drive the flyweight mechanism and absorb its acceleration/deceleration loads:
I think the roll pin probably shears first, which leads to the advance mechanism slipping on the shaft, which loosens the skinny little screw, which lets the whole works wobble, which breaks off the screw at the threads as shown. Regardless, I have now fixed this for the last time. Yes, when it failed, I had spares in my tool kit. There was, obviously, a reason I carry them. This was the third time in my 43 short years of ownership this has happened. Enough is enough.
So, I bought a full-up, fully programmable, pointless and flyweight less electronic kit known as an "Ultima":
The little cad plated cup is the trigger wheel, replacing the entire advance mechanism. This kit is a "single fire" setup, instead of the "dual fire", or "wasted spark" of the original ignition. It has a new split coil, the programmable "brains", and everything else needed.
All I can say, after installing this unit, is "holy smokes". It's a whole different bike. I had previously this year upgraded to a Pingle high flow petcock. Their motto is "don't let your petcock act as you your main jet". I think that is exactly what was happening with my original stock petcock - its flow was inadequate under full throttle. Between these two upgrades, the bike has simply taken on an entirely new personality. It has never run so well. Noticeably more power, better throttle response, much better idle, just everything is better.
I've normally been, admittedly, somewhat jaded regarding modern "upgrades" to vintage machines. Granted, the petcock doesn't qualify as such, but I have also replaced the old Bosch points type voltage regulator with a modern electronic unit. I now have to concede that these specific upgrades have made this old bike a much more "usable", and certainly more reliable machine. I've now drug her kicking and screaming into... the 1980's. And she's a better bike for it.
Funny how a couple of breakdowns and roadside repairs worked out.