Hi all spark issues and burning through points

[Rusty]

Hello all, trying to get the bike working before warmth like most of you. So, little history 68 Ace 100, I sent the magneto off to Roger Lippiat because I was busy at the time and he's awesome and I live in Ohio. He replaced the coil, points and sparkplug wire on main coil. Got it back and the bike ran great. Then i lost spark, I checked the points and one contact was completely gone. He was a bit puzzled and was kind enough to send another. Again bike ran great, loaded it up to do some trail riding in Michigan. When I got there darn thing wouldn't spark. New plug, did point gap, no go. Anyway just had a chance to take off the flywheel and the points look nearly gone again!! So before I buy new points was wondering why this is happening so I can fix it (hopefully) and don't have deal with this again. Thanks everyone.

[Dale]

Most likely a faulty condenser. It could have been NOS and just gone bad or it could have gotten too hot during installation. Less likely, but possibly a cold solder joint.
Dale

[Zyx]

The only thing that religiously burns points is a bad condenser. Sounds like parts supplies quality is slipping some too, or maybe not. But if you have a multimeter that tests capacitance, check the condenser. If you have to buy one, buy two.

The condenser, among other things, limits the arc of electricity across the points when they open. Without this in place, there is a more substantial arc of juice across the points every time they open. That can run to several thousand times a minute, so it doesn't take long if the condenser is bad to burn off the point contacts.

Dale points out something important. The condenser is soldered in. Soldering right on top of the can will get the innards hot quickly. To do this right, you need a fairly hot iron to limit time needed to make a solvent joint. Too cold an iron takes too long to heat to the melting point, and just dumps heat into the condenser. So a quick, clean, hot solder joint, and cool it off quickly if you can. You can blow on it, or use a damp paper towel and just touch the solder joint, but make sure it is clean and set before chilling it. You can see when the molten solder flashes over, then you can use a damp cloth. This limits heat soak in the condenser.

[Rusty]

Thanks, yes I have a multimeter. What setting and what should it read? I imagine Roger is pretty qualified at soldering, it's a nice joint, he's been doing this a long time. I'm not sure if its a NOS cap. I know electrolytic caps have a shelf life.e Thanks for the info, guess I gotta buy new points and condenser.

[Zyx]

Capacitance is 0.25 to 0.27 Mf, plus or minus 10%. Meter set to capacitance, which is a funny symbol that looks like a
vertical bar and a parentheses with hyphens on both sides, the meter should read in "F ". Farads if I remember right. I think the rating for the condenser is in microfarads. Give it a few seconds to try to load the condenser with a charge before deciding on the condition, and it should be electrically isolated from the points, so unhook the lead.

[Rusty]

Thanks all, Roger is sending me a new condenser and points. If you ever get a chance to talk to Roger it's a treat! He knows his stuff.