NS$ Magneto Polarity question.

[partshunt]

I need a few people to take a compass over to thier NS4 magneto on thier four and tell me if the left side of the mag attracts the North indicator needle. I believe the outside should be the North pole and the inside or right side sitting on the bike will be the South pole and has the red paint match marks indicating South pole. I have another NS4 that may have been magnetized backwards so I need a few examples from several mags to either prove or disprove my suspition. Thanks and all the help I get on this hopefully should settle a long nagging issue with the guy that did the job on the one mag in question..You wont need to take anything apart, just use a compus to check polarity,....thanks...Joe

[Indiantim]

Hi Joe

My magneto is off at the re builders at the moment, I will ask him to do this check, he wants to know what is the direction of rotation viewed from the drive end for a Splitdorf for an Indian 4

[partshunt]

NS4 Rotation

Viewing the drive end, the NS4 Mag rotates counterclockwise....Also, be sure there are paint marks on one side to reinstall the poles back correctly. Normally red paint is used and is on the right side or the side closest to the cylinders on an Indian Four.If none is present, have the rebuilder repaint this area before disassembly. My only question is, was the red to indicate North or South pole?, that mystery, I am not certain of...Joe

[Tom Wilcock]

Joe: At last I remembered to buy a compass when I was in town. On my NS4 mag on mt 1929 basket four the left side of the mag attracts the south pole of the compass. I guess that would be the north pole of the magneto as opposite poles attract. Hope this helps. Tom

[partshunt]

Thanks Tom:- Your mag coinsides with my weak magneto. Sorry you had to buy a darn compass but they are usefull around magnetos. Especially when takeing em apart, you can record and confirm pole positions. Thanks, much apreciated. Hopefully more examples from others will indicat somewhat that my mag wasnt remagnitezed backwards. Are there any painted match marks on the inside or outside of that NS4 magneto?...thanks..Joe

[Tom Wilcock]

Joe: I should have a compass anyway so I should not get lost as often (now If I could only find the light switch). There are no painted markings on my mag. I took it apart and there are no marks on the magnet or frame. The coil and capacitor are painted red but nothing else. Tom

[partshunt]

Thanks Tom: Something I realized and Googled was the fact that the North Pole on earth is really a South Pole. Isnt that nuts? I always thought the North Pole on earth was a real North. At my age, its embarassing to admit it. Still learning something every day. So, like you say, your left side repels North, so its gotta be a South Pole on the outer side when installed on the engine. All info is helpfull....Joe

[gharper]

OK, I've looked at a dozen different Splitdorf magnetos in my collection and things got even muddier. So, I looked in some Splitdorf service manuals that I have and found the following. Remember that when referencing rotation of the magneto, it is ALWAYS when looking at the drive shaft end. Right hand rotation means Clockwise, Left hand means Counterclockwise.

Quoted from the Splitdorf model C magneto manual:

"......The magnet must be charged so that the pole marked "N" is made the north pole. For right hand magnetos the "N"pole is on the right hand viewed from the drive end. For left hand magnetos, the "N" pole is on the left hand viewed from the drive end. The north pole is regarded as the north seeking pole, or the one to which the north pole of a compass needle is attracted......" (The model C magnetos have the magnet exposed and are stamped N on the north pole)

Quoted from the Splitdorf model S and NS manual:

"Care should be taken to magnetize magnets and replace them with the same polarity as when removed from the magneto. The north pole of the magnet and corresponding position on frame is marked in red when magneto is manufactured."


There you have it, straight from the bible! Hope this clears things up for you.

Gene Harper

[partshunt]

Gene:- Thank you very much for takeing the time to do all that research. The weak NS4 mag that was so hard starting coinsides with your information and am pleased with that. It means the magnetizer correctly remagnetized the poles but he musta made another error, possibly did not slide the poles on to a keeper plate. The muddy part is that the good mag which is on my four is oposite polarity wise but it has a tremendouse spark and I wont be disturbing it. The four starts so easy now with the muddy mag, gonna leave it on till I address the other (weak) mag and get it really working good. I call the good mag a muddy mag due to its reversed polarity but its a great mag, not rebuilt like my weaker mag is. This info you have submitted takes me to another question. I would think the engineers would want the armature rotating against the magnetic direction of flow to get maximum induction. So the question arrises, which way does the magnetic field flow, from south to North? Remeber too that the North seeking pole is really a South pole since it attracts the North needle. Unlike poles attract, like poles repel... BTW, both NS4 mags are Indian 4 spec # 2588....So my question now is which way does magnetism flow?, I could not find that in Google....Joe