Petter A1 magneto strip down

Hi, I posted question a while ago about issues with my Petter A1 wipac magneto, and was advised that there was an issue with the spring mechanism and advised to strip, which I have now done. Please see the attached, it looks like there should be 2 "arms" which engage in a clutch like mechanism via a spring, but as you can see from the image there is just one. Not sure where the other could have gone because there is no evidence that it has been stripped recently, indeed one of the weight pins was brazed in!
The drawings one member kindly sent me do not show this mechanism, so I guess slightly different model, can anyone advise if I should have 2 such arms? If so what are they correctly called, so I can attempt to source replacement (or make one!).

I have searched for video of magneto rebuild, could anyone point me in direction of video, or drawing?

Thank you for your continued support

Hi, thinking about it a little more, I have another question, as well as the 2 "arms", should there be any further springs, other than the large torsional spring, or any other bits missing? A drawing or photo would be very useful right now!

Thanks again

There's only one arm and one spring. That arm should move. What other parts
did you take off.
Andrew

Hi Andrew, thank you for your reply. Apart from the cover (which had the torsional spring) the only part I removed was a plate which went over the 2 pivot pins/arm. I am assuming that the arm should also have a spring? Should there be any other parts?

https://servimg.com/view/20299532/7

I thought I would take a quick snap of the other bits I removed, ie the cover containing the torsional spring and the plate. There were no other parts, or spring on the arm

Hopefully only 1 copy will upload!

Try this...

https://www.antiquetractorsrus.com/images/products/detail/WicoXHandXHDDiagram.jpg

Thanks look like I am missing a small spring, circlip and washer. Do you know of any images/videos of the assembly?

Hi Michael, looks like you started two threads - may I delete the unanswered  one?

Apologies, I had different question, so thought a new thread was appropriate

Michael.parker4 wrote:Apologies, I had different question, so thought a new thread was appropriate

No worries.

Hi, I need to beg some more assistance on the re build of my magneto, because I am at a loss. I think that the main issue I have is that I do not understand what this mechanism is doing! (Please forgive my ignorance, I am new to magnetos). Appletop kindly directed me to a drawing, but this is labelled 2/4 cylinder, and mine is single cylinder, so not sure if relevant?
Does anyone have any drawings, or images of the assembly of this mechanism? A rough free hand sketch of how this goes together would be greatly appreciated

Thank you for your help

Hi Michael,

Can you let us know the precise magneto model please - my Petter A1 / A2 manual lists WICO A1056BZ.

If nobody comes up with a better offer, I have a JAP manual that has an exploded diagram of a WICAP CJ 936 which might give you a bit of a clue. I also have a 'generic'  document on impulse couplings.

Hi Paul, thanks for your reply. The only markings I can find is on the cap, and it just says "series A". I attach image of cap and side view if this helps?

The main difference with your mag and the 2/4 cylinder one I shared the link to is the distributor and end cap, everything else is relevant to your questions. The mag type would be on a brass or ali tag fixed to the casting on the drive end, between the bakerite cap and the mounting flange. There is some info online about rebuilding these, not much as it doesn't translate to well to tinterweb...

Hi, if there were any tags, they are long gone, the only brass tags are the oiling instructions.

I did find a number hand engraved on the casting of A940, but this looks more like a serial number!

Have a look here, there are some 20 pages of data on Wica A magnetos.

http://www.oldengine.org/members/diesel/WicoMagneto/MagData4.htm

Thanks Blue cat, that will be very useful, I will have a look later (when it warms up a bit later and I can feel my fingers!).
Has any taken a photo of this stage if the assembly so I can work out how it goes together? I am still trying to work out what this does (which will help me understand how should function). Is it to give a kick to boost the spark, or is to to give advance to the spark timing?

Thanks for your help, once I can get a spark, just need to strip the carb, make a couple of little bits, then start up time!

Its to give a kick to boost the spark, the magneto is timed as per the manual.

Maryalice

Thank you Maryalice, now I know what it is suppose to do I can try to understand how it works, and then how it goes together!

Michael.parker4 wrote:Thank you Maryalice, now I know what it is suppose to do I can try to understand how it works, and then how it goes together!

Hi Michael,
The 'generic' document on impulse couplings I mentioned before explains exactly that. PM me if you want a copy.
'

[quote="maryalice"]Its to give a kick to boost the spark, the magneto is timed as per the manual.

Maryalice[/quote]

Also retards the timing....

Hi..... thank you all for your help, now have Impulse coupling working, but still no spark! I am getting voltage because I can get a shock if I touch HT, but not enough for spark, either at plug or spark tester. I figured it could be condenser, so I have just replaced that, no difference!
Points look good, so just cleaned and set them. New leads (zero ohm) and plug, so all that is left is the coil?. I am not sure how to check a coil?. I have removed it and measured all the resistances of the 3 leads, HT, lead going to condenser and lead going to earth, with following:
HT to earth - 5k
HT to condenser - open
Condenser to earth - open

Can anyone advise if these readings are normal, or if it looks bad? If bad does anyone have one for sale, or know where to get one?
Thanks for your help

Go to oldcroak.com they have manuals and parts,you may have to request manual,one rhing you can try is to put coil in oven or near furnace to dry it out,oven temp at its lowest,ive herd that if theres moisture in coil it will short out so to speak or it doesnt go thru all windings

shiftless wrote:Go to oldcroak.com they have manuals and parts,you may have to request manual,one rhing you can try is to put coil in oven or near furnace to dry it out,oven temp at its lowest,ive herd that if theres moisture in coil it will short out so to speak or it doesnt go thru all windings

If coil is damp and faulty drying it wont cure it as windings are loosing insulation, find who your local repairer is and get it rewound, buying other coils of unknown quality is a waste of money unless you get them repaired. It wont be cheap but in the long run will save you time and money.

Maryalice