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D6 9U pup mag problems

D6 9U pup mag problems

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DDDfarmer
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Well if finally happened, the mag on my pup quit. Ran good three weeks ago, then last week..... sparky dont spark. first pulled the cap, everything looks good. Cleaned the points and checked the gap... ok. Interior of the case was very dirty so with some brake cleaner and lots, lots, lots and a lot more air cleaned it out. Then I pampered the misses and while she was relaxing I placed the mag into the stove on low heat for a few hours..👍


I should mention that the rotor was covered with what looked like hair line cracks. One of the many install - removall of the cap I didn't have the rotor into place right and on a test spin the rotor shattered and broke the wire brushes. Minor setback right? how much can a cap and rotor cost? Well at least I can borrow the cap and rotor from the D4.


Tonight I grabbed one of our spare tractor condensor and installed in place of the original in the mag. Turn the mag over by hand and nice blue sparks at the points, problem solved right?

Placed the mag back onto the pup, cranked it over and nothin. No spark at the points or the plugs. So now its time to modify.

I had called CAT today for some prices and what can I say but WOW !!!

Cap, 210.35
rotor, 134.05
Points, 35.45
Condensor, 29.88
cap gasket, 9.10

After got off the phone I realized that you could order the brushes to repair the cap. Does anyone have any experience in replacing the brushes? unless the brushes cost more than an arm it looks like repair is the way to go.

To have the mag rebuilt would run $300 or so, to add an external coil might cost $40-$50 once its done.

Any recomondations on a external coil that works better than others? I have some coils around for older gas farm tractors. I'm thinking to drill a hole in the case right below the coil tab and make a pressure plate to match then attach to the hot wire. Simple and effective.

I just want to get the tracks turning again. lots of mud and trees to push.
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Tue, May 8, 2012 9:32 AM
212richard
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A nice big blue spark at the points is exactly what you DON'T want. The purpose of the condenser is to shoot voltage back through the points the instant they open, to keep a spark from occurring across the gap. There are two reasons for this. One is that arcing erodes the points, and second, the primary field in the coil won't collapse until the points have separated far enough to stop the spark. Depending on the voltage in the primary circuit at any given TDC, (mag RPM can be one factor) the points may require greater or fewer crankshaft degrees to break the primary circuit, resulting in the spark in the secondary circuit occurring anywhere around TDC. The condenser keeps the ignition timing consistent. It sounds like your condenser is bad. Try another one, it doesn't matter where it comes from, for test purposes. I would also take the mag off and clean up the interior. If this was a sudden failure, that cracked cap may be giving you problems due to moisture.
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Tue, May 8, 2012 11:37 AM
212richard
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Reply to 212richard:
A nice big blue spark at the points is exactly what you DON'T want. The purpose of the condenser is to shoot voltage back through the points the instant they open, to keep a spark from occurring across the gap. There are two reasons for this. One is that arcing erodes the points, and second, the primary field in the coil won't collapse until the points have separated far enough to stop the spark. Depending on the voltage in the primary circuit at any given TDC, (mag RPM can be one factor) the points may require greater or fewer crankshaft degrees to break the primary circuit, resulting in the spark in the secondary circuit occurring anywhere around TDC. The condenser keeps the ignition timing consistent. It sounds like your condenser is bad. Try another one, it doesn't matter where it comes from, for test purposes. I would also take the mag off and clean up the interior. If this was a sudden failure, that cracked cap may be giving you problems due to moisture.
When you put the mag on the tractor and there is no spark, remove the kill wire from the mag to make sure the problem isn't somewhere else.
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Tue, May 8, 2012 11:43 AM
Cobalt Kid
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Reply to 212richard:
When you put the mag on the tractor and there is no spark, remove the kill wire from the mag to make sure the problem isn't somewhere else.
Good day DDD Farmer,

Just wanted to say that maybe give GemDozer an e-mail as he has helped myself and many others with his parts supply. He is usually on here from time to time.
He is in Quebec and his parts are good, and prices are reasonable. Not sure where you live in Northern Ontario as far as the shipping costs.
As for myself living in Cobalt shipping prices were fair.

Just my 2 cents,
Hope this helps.
Cobalt Kid
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Tue, May 8, 2012 7:49 PM
gemdozer
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Reply to Cobalt Kid:
Good day DDD Farmer,

Just wanted to say that maybe give GemDozer an e-mail as he has helped myself and many others with his parts supply. He is usually on here from time to time.
He is in Quebec and his parts are good, and prices are reasonable. Not sure where you live in Northern Ontario as far as the shipping costs.
As for myself living in Cobalt shipping prices were fair.

Just my 2 cents,
Hope this helps.
Cobalt Kid
I could sail you a complet D6-9U magneto AMERICAN BOSCH for $200.00 the mag can be shipped C.0.D by CANADA POST
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Tue, May 8, 2012 8:43 PM
DDDfarmer
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Reply to gemdozer:
I could sail you a complet D6-9U magneto AMERICAN BOSCH for $200.00 the mag can be shipped C.0.D by CANADA POST
212richard,

yes I guess its possible to have a bad new condensor I can replace with another and try. The kill wire has been disconected one of the first things I tried. But if the cap is not on and there is no place for the current to go shouldn't there be some spark at the points?


Cobalt Kid,

I'm 2 1/2 hours north of you in Cochrane. Thanks for the info for Gemdozer my new parts man.



Gemdozer,

there is a Pm in your mailbox. Thanks.
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Tue, May 8, 2012 10:30 PM
DDDfarmer
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Reply to DDDfarmer:
212richard,

yes I guess its possible to have a bad new condensor I can replace with another and try. The kill wire has been disconected one of the first things I tried. But if the cap is not on and there is no place for the current to go shouldn't there be some spark at the points?


Cobalt Kid,

I'm 2 1/2 hours north of you in Cochrane. Thanks for the info for Gemdozer my new parts man.



Gemdozer,

there is a Pm in your mailbox. Thanks.
does anyone have the proper procedure to dis-assemble a mag? I guess that if its not working I cant make it any worse...right? If I could open it up to the coil and leave the gears alone everything should be ok.
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Tue, May 8, 2012 10:35 PM
DDDfarmer
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does anyone have the proper procedure to dis-assemble a mag? I guess that if its not working I cant make it any worse...right? If I could open it up to the coil and leave the gears alone everything should be ok.
Well she's running again, got another magneto from gemdozer and WOW. Now I understand why they say there is a difference between a ok mag and a good mag. With the original mag the pup would start after cranking for a little while, tonight with the new to me mag second revolution it was running. And there was no hit and miss just running all out.

Local shop might be interested in the challange of repairs to the old mag, said to bring it in sometime.
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Tue, May 15, 2012 9:31 AM
Cobalt Kid
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Reply to DDDfarmer:
Well she's running again, got another magneto from gemdozer and WOW. Now I understand why they say there is a difference between a ok mag and a good mag. With the original mag the pup would start after cranking for a little while, tonight with the new to me mag second revolution it was running. And there was no hit and miss just running all out.

Local shop might be interested in the challange of repairs to the old mag, said to bring it in sometime.
Was reading your message and noticed that you have a D4. Was wondering if you have any spare parts for her. I have a D4 7U and am in need of a few parts.

Cobalt Kid
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Fri, May 25, 2012 10:23 PM
gemdozer
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Reply to Cobalt Kid:
Was reading your message and noticed that you have a D4. Was wondering if you have any spare parts for her. I have a D4 7U and am in need of a few parts.

Cobalt Kid
If you can't found some D4 used parts near your place maybe I could help you .
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Sat, May 26, 2012 6:52 PM
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