Sparking ignition points

[Gorminrider]

well, that's progress! I do wonder though,as a very simplistic approach, if "larger" capacitors (with a higher uF) might help-they wouldn't be much larger physically.

You can ADD capacitance too- in "parallel"- they would attach the same places. This'd be a simple experiment to see if more helps.
Capacitors can be roughly tested with a multimeter too, just to try some used one as the additional....

[John Park]

well, that's progress! I do wonder though,as a very simplistic approach, if "larger" capacitors (with a higher uF) might help-they wouldn't be much larger physically.

You can ADD capacitance too- in "parallel"- they would attach the same places. This'd be a simple experiment to see if more helps.
Capacitors can be roughly tested with a multimeter too, just to try some used one as the additional....

Capacitors don't have to be next to the points. They can be up at the coil and work as well or better. I think they put them beside the points for reasons of one stop shopping. They just have to be between the points wire and ground. This is a common mod on 'behind the flywheel' points/capacitors where the heat and vibration is intense, and also for racing where quick access is a priority.

I've often wondered what the effects of too much capacitance would be. I think the function is to absorb the kickback from the coil's primary winding, in which case more would be better. At some point more would probably just be irrelevant.

I remember seeing a somewhat disturbing amount of sparking on my old points GSs back in the day. Points life wasn't very good, but the rubbing block would wear down anyway so it all worked out. I'd still prefer to have points and a spare set in the toolkit than have to deal with a shot ignitor halfway to nowhere on a 40 year old bike.

[Gorminrider]

good idea! yes they don't need to be on the points plate.

Take my musings with a grain of salt but Yes, they absorb the kickback from primary ....

but they discharge it, too at the earliest opportunity when the points close. Usually they discharge anything they can harmlessly. ie: polarity of the "discharge" being opposite that of the ground, so they fall to 0+ volts very quickly.
However (hurting brain now
If the OPs leads were swapped at the primary-(I'm thinking of a very simple coil here-might be impossible to wire certain coils backwards) well, I'd expect it'd change the capacitor's polarity too, Then, it would be discharging in the same polarity as the bike's so it would only discharge to the bike's 14 volts? This WOULD reduce capacitance and render them useless because they would always be charged and only "take up" voltage higher than the background 14vdc....? I did say lick the salt shaker while reading this.

Firstly, In my limited experience, I can't think of a time I've ever had too small a capacitor-twas just a thought that might lead the long way to fixing the OPs observed sparking ...These automobile-type capacitors are basically a kind of very fast-charging low-voltage battery . These low voltage types can have their "plates" very close and with their size, and big "plates" they can store quite a lot of current. but they can only store so much even so. They needn't be "fully charged" to function so I don't think you can have "too much" capacitance in this application.

[John Park]

Electrolytic capacitors are polar, but I don't think these ones are. Electrolytics don't age so well; I think the electrolyte dries up. I'm currently - pardon the pun - running the original capacitor in a 50 year old bike so I doubt that there's anything fancy in there. Typically, electrolytics are used for smoothing rectified DC and are probably not necessary here; they also cost too much. But I'm open to being surprised. Regular capacitors are non polar.

As you say, a capacitor is a just a form of battery. They now have super capacitors that could be used for electric cars but the effects of instantaneous discharge pretty much sour that concept. Lightning strikes the Toyota. But they could be used for regenerative brake storage that a Li ion is too slow to deal with. Gas cars burn; electric cars smoulder until they explode. Donkeys are pretty safe. Slow, and you don't have so far to fall.

[Gorminrider]

Yes, they are pretty much tinfoil and paper rolled up as layers...You can actually make one. The symbol " || " on a diagram means no polarity versus ")|" which is DC . Points system is pretty reliable-but the TCI is so easy and also reliable IMO..but, I have a working spare TCI I can carry on a long trip...

I'm having a look 'round online and there's plenty of prose written about these capacitors! (I've lost the habit calling them "condensers")
One thing to note from "looking around" is that "they don't make em like they used to" is a common complaint, so testing a spare in place is a good idea.

[John Park]

Yes, they are pretty much tinfoil and paper rolled up as layers...You can actually make one. The symbol " || " on a diagram means no polarity versus ")|" which is DC . Points system is pretty reliable-but the TCI is so easy and also reliable IMO..but, I have a working spare TCI I can carry on a long trip...

I'm having a look 'round online and there's plenty of prose written about these capacitors! (I've lost the habit calling them "condensers")
One thing to note from "looking around" is that "they don't make em like they used to" is a common complaint, so testing a spare in place is a good idea.

When I was a lad the '53 Studebaker I was riding in had a capacitor failure - incapacitated, so to speak. The owner was an electrical engineer and he used the licence plates and some wax paper from the lunch sandwiches lashed together with the plate bolts as terminals and hooked it to the coil lead and ground. It went a hundred miles home with the only glitch being pulled over for no plates and having to show the cop what was under the hood. Considering that we were fifty miles from anywhere on a Sunday it would have been a long day into the night walking. I was led to wonder how many uF a pair of licence plates produce. Enough, apparently.

[Gorminrider]

Hah! What a great story!

but sure! why not? there's plenty of electrons with nothing better to do in licence plates! I wouldn't be suprised if that wasn't like Faraday's original experiments.

[Chancho196]

My 1980 GS550E was fitted with the Kokusan system and i fitted several different condensers to it, including NOS. No matter what I did, intermittent sparking across the points kept occurring.

Also, points that have been cleaned with wet & dry are apparently rendered useless due to the material being embedded in the surface. Because I was fed up with wasting money, I fitted the Dyna system when I did the 673 conversion. That setup is great but, being a bit old-fashioned, I would've loved to have kept the points.

[John Park]

Hah! What a great story!

but sure! why not? there's plenty of electrons with nothing better to do in licence plates! I wouldn't be suprised if that wasn't like Faraday's original experiments.

Well, it was good enough fer a day.

[Brendan W]

When I was a lad the '53 Studebaker I was riding in had a capacitor failure - incapacitated, so to speak. The owner was an electrical engineer and he used the licence plates and some wax paper from the lunch sandwiches lashed together with the plate bolts as terminals and hooked it to the coil lead and ground. It went a hundred miles home with the only glitch being pulled over for no plates and having to show the cop what was under the hood. Considering that we were fifty miles from anywhere on a Sunday it would have been a long day into the night walking. I was led to wonder how many uF a pair of licence plates produce. Enough, apparently.

So did he want to charge you for no plates but then realised they were charged already ?

[John Park]

So did he want to charge you for no plates but then realised they were charged already ?

He was just acting in his official capacity.

[Grimly]

He was just acting in his official capacity.

Was this in Alaska? He would have had a cool 'ome to go to.

[Gorminrider]

.......

Also, points that have been cleaned with wet & dry are apparently rendered useless due to the material being embedded in the surface.

Yes, I've heard this too and likely have ruined some wrapping wetndry around popsicle sticks...relays in general-same thing. There's actually a tool "beyond" a points' file called a "burnisher" that I found at a yard sale...It makes me feel pretty special when I get to use it!

[Gorminrider]

So did he want to charge you for no plates but then realised they were charged already ?

(funny!) It could have been worse potentially.

[John Park]

(funny!) It could have been worse potentially.

Nah,.....we had connections.