Misc: Ignition Unusual sparking at magneto contact breaker assembly. (with video clip)

[Paul Coene]

From the Brightspark website:
A number of people have mentioned that if the old condenser has failed completely open circuit, then there is no need to disconnect it. That is true. However, condensers commonly fail in other ways, and it is nigh on impossible to tell whether a condenser has failed open circuit without disconnecting it from the LT winding.

Brightspark - Condensectomy

 

[timetraveller]

It is correct that the original condenser has to be disconnected. It is several years since I helped to do this conversion but I remember there was some problem locating just how many wires had to be cut in the armature. It was something like the instructions said three but only two were visible and it then turned out that one of the wires was doubled up. Whatever it was becomes clear when one starts to do the job. Sadly the chap who I helped died a year or so ago so I cannot go back to find the instructions. If those wires were not cut or disconnected then that could certainly cause trouble.

 

[Magnetoman]

I always hesitate to jump into electrical threads until the poster has revealed all the relevant secrets, which they never seem to do until after a few posts. In the first post we learn a new washer was installed, tempting us to blame it. But, was the problem there before the new washer? He doesn't say whether or not it might have been there, but only noticed now. He also failed to tell us until a later post there's a non-original condenser clamped where it doesn't belong and flying around in the blur of his video.

Anyway, the white spark happens at 7:00, as it would if at the points. We need a photograph, not a video, of the magneto in question when the points are about to open at 7:00 so we can see what it looks like at 5:00 where the yellow lightning storm is located.

 

[Paul Coene]

I always hesitate to jump into electrical threads until the poster has revealed all the relevant secrets, which they never seem to do until after a few posts.

Please try to understand that sometimes amateuristic ignorants hope that there might be
someone who, after watching a suchlike clip, anwers that it is nothing unusual, being often noticed and gives a clear explanation.

In the first post we learn a new washer was installed, tempting us to blame it.

I had no intention to tempt you to blame it. I mentioned it to make clear why the magneto had to be overhauled. During this process, maybe something went wrong.

But, was the problem there before the new washer?

As I wrote, the magneto shaft showed a radial play so this had to be examined and solved first. Even if I am a photography enthousiast, I don't have the habit to make video's of my magneto contact points very often so I don't know. And I never mentioned this yellow sparks as a problem. Maybe they often occur with this devices. Read #1 again: I only asked if someone could explain it.

He doesn't say whether or not it might have been there, but only noticed now.

Are you talking to me ?

He also failed to tell us until a later post there's a non-original condenser clamped where it doesn't belong and flying around in the blur of his video.

Anyway, the white spark happens at 7:00, as it would if at the points. We need a photograph, not a video, of the magneto in question when the points are about to open at 7:00 so we can see what it looks like at 5:00 where the yellow lightning storm is located.

Taking the risk that again you will blame me that I didn't provide you with this information right from the start, I'll post some still frames. And no, I don't have taken any photos. I captured that video-clip with my portable phone.

 

[Paul Coene]

Studying the video clip in detail, I noticed those yellow sparks appearing twice: once at 06:23 and once (bigger ones) at 07:05

I think the first photo (6:23) is interesting as you see a little white spark on the left, most probably between the contact points) and at the same time the yellow ones beneath. This -I think- gives an indication of the position of the contact points at the moment of the yellow arcing.

 

[timetraveller]

In the olden days when I used to play with magnetos I watched the points rotating with the engine running on several occasions. I have never seen anything like the yellow spark but it cannot be a good thing. Even trying to superimpose the image of the spark on Magnetoman's still image I still cannot imagine where it is going from and to. It is possible that one end of it is the fixed heel of the points but the other end ?the central bolt ??

 

[greg brillus]

Perhaps because the brightspark condenser is mounted to the points plate, it is looking for an earth return........if the spring and points plate brush are missing, it might be trying to find an earth, and this is the arcing you can see........ If you undo the points screw and remove the points aasembly, you will see if this spring and brush carbon are there or not.

 

[Paul Coene]

Eureka !

Using the still frame of 06:23, I could locate the place of the sparks. I removed the point assembly and found the spring of the contact points being in contact with the circuit board of the Brightspark condensor.

Removing the circuit board in that area should solve the problem. Not even necessary : the spring can be moved easily enough to give the required clearance.

Thanks for thinking with me !