Shovelhead Ignition Help

[NZT100]

Hi guys,

Have gotten my bike up and running and been working through everything verifying correct running conditions but I’ve noticed something that doesn’t add up to me, however may be nothing. Every 3rd to 4th fire of the spark plugs I’m getting a double spark, as in both plugs fire twice on one break of the points.

Bike is 74” shovel, Running points, Dyna coil, new leads and plugs, new battery, points are what was in it, blue streak condenser. Timing is set as per factory manual and verified correct via static and advanced positions, I have strong spark, good compression, no manifold leaks, carb static tuned as per S&S guide. Tested primary coil circuit and is 2amps, secondary within spec.

I tested the condenser with a multimeter and it shot up to max on my multimeter within two readings, ie 1.5million ohms, then maxed out, based on what I read this wasn’t a definite “Tested ok” condition. It was holding charge and I could discharge and recharge it. Maybe an issue here?

Second probable cause could be the points themselves. When setting timing I was getting a visible blue arc just as they were opening. The points them selves have a strange cam runner thata like an L shape laying on its side, not sure if they’re stock or not but it did make setting the gap at max open harder than normal.

Any hints or advice on what could be causing this double spark condition would be great . At this point I’m thinking about replacing the points and condenser and calling it’s day but I’d love to understand what is causing this and WHY.

Thanks for any help. Andy.

[rhysmort]

Good morning mate.

Firstly, congrats on getting her together and running.

Might be worth getting some pictures on here. Speak a 1000 words. Is it running strongly? Even with the issue with the points? under load? idle? Points are pretty fool proof, so unless you have some whacky cam as you mentioned, once they're set they are usually good to go.

How worn are the points? Are they newish? may be good practive to get them changed.

[NZT100]

Thanks Rhys,

I'll get some pictures/video tonight. Once its running it is running well in general, it does stumble at idle after about 10 seconds and die sometimes but I've left that out as its more likely carb tuning at this point.

Points themselves are in good condition, I cant see arcing during running only during kicking over slowly to set the points. My thinking is ill just buy a replacement set and give it a go, if it turns out its nothing at least I've got a spare set then.

[johnjzjz]

i know its more money - but a dyna S ignition is the go to for us in the shop

both the points and condensers are questionable at any time even new Today not like it was even 10 years ago