Ground wire on magneto burnt, is this common?

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AJAGLASS

New Member
Mar 15, 2010
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Forestville
Hello, my bike died the other day after going for a few miles. some uphills might of strained my magneto? All of sudden bike died, no spark, I ran through all trouble shooting techniques with no luck. I took the magneto off and noticed a small wire, that looked burnt, coming out of the side of the spool of wire on the magneto. I touched it with an incense stick, and it fell right off.. I ended up digging out the wire with my solder iron and resoldered to body of magneto. I am going to test tomorrow, is this common?zpt
 
2door

2door

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Sep 15, 2008
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What do you mean by "I soldered it to the body of the magneto"? There are two wires, blue and white that should be connected to the magneto coil.(there are two very very small wires that come out of the mag coil) The black wire, the ground, has an eyelet terminal that attaches to the mag core by way of one of the mounting screws. If you soldered a wire to the "body" of the magneto, which one and exactly where did you solder it? Tom
 
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AJAGLASS

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Mar 15, 2010
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Forestville
[well if you look real close there is a solder point on the right side of the spool.. I have used a pen to point to it.. the wire was so small coming out of "side" of spool. I noticed a solder blob at first. then after inspection, I just barely bumped the little wire, and it just fell off, I had to dig, what was left out of the side of the spool with my solder iron. I just got barely enough wire to solder back on to the magnet, I even had to heat with small torch to get solder to stick on thick metal, you have to put a heat sheild in between, like a flat head screwdriver. Then I used a little bit of a glue stick to seal back over side of spoolPicasa Web Albums - AJAGLASS - bad magneto w...
 
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2door

2door

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Sep 15, 2008
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For some reason my browser will not open your photo but from your words it sounds as if you soldered a wire from the mag coil to the laminated frame, or core, of the magneto. That won't work. If you damaged the windings by digging into them you've probably destroyed the coil. At this point you'd need a very good ohm meter to determine the resistance of the coil but even that will not assure that it is good. I'd suggest you order a new magneto from one of the sponsors here and start over. The soldered connections on the coil are very small and delicate. The windings of the coil are extremely fine wire and the wire has an insulating coating to keep it isolated from itself. Damaging that insulation will change the resistance of the coil and either short it or shunt it, either will make it inoperative. Get a new magneto; they're cheap. http://thatsdax.com/ENGINE_KIT_PARTS_PAGE_1.html or try here also
http://www.pistonbikes.com/product-p/epe47.htm

Tom
 
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AJAGLASS

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Mar 15, 2010
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Forestville
I know it is a long shot, but I think, I might of been able to solder ok?. there was just a little wire still in the side of spool that I used, I did not unwind or anything, I don't think I overheated, but there is a chance. trying to save $$, and I dont have an ohm meter. It would not hurt anything to try, I suppose, so I am going to try it any way..
I have been having problems resizing pics in picasa. I can not upload pics directly from my comp, to forum, because they are too big, and picasa does not let you resize with out uploading or emailing pic. I have looked online, and there have been problems with picasa.... I guess I could resize another way..
 
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AJAGLASS

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Mar 15, 2010
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Forestville
I just made the pic my profile picture, try link again , picasa is having issues, it might take a while, and try to click on pic migh help, or not.. the pic does not show much anyways, thanks for advice[
 
2door

2door

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Apparently you've had problems prior to this. I see two red wires coming from the magneto coil. Where did they come from? Every magneto I've ever seen for these little 2 stroke engines regardless of the manufacturer use a blue and a white wire to the magneto coil. Two red wires are not the way they come. How do you know which is which? The blue wire is the ignition primary winding and provides current to the CDI. The white wire would be for a low wattage headlight. The engine would not run if the white wire winding of the magneto coil was used for ignition. Where do those two red wires go?
There should be nothing soldered to the core (frame) of the magneto. One wire, the black one, or ground wire does attach to it, as I said above but the other two connection points can not be connected, (grounded) to the mag itself but must remain isolated. You can try your repair but I'm sure you'll be buying a new mag very soon.

Edit:
I just went back and looked at your photo and I had previously missed the lettering on the coil identifying the blue and white connections. Sorry. Just don't mix those red wires up at the other ends.
Tom
 
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AJAGLASS

New Member
Mar 15, 2010
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Forestville
.shft.Success, the bike is running stronger than ever. The only reason why I used only red, because that is all I had. The original wires were not soldered very well.. I did mark them, and I hooked up correctly.. To do with the little wire coming out of the side of the spool, I am sure that that was the problem. You can see pictures on internet of a new magneto, that has the same ground point soldered to body of c shape magneto next to spool on the blue side Good thing I know how to solder. Saved $$$$$ I have done this with no ohm meter, just by visual inspection.
 
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AJAGLASS

New Member
Mar 15, 2010
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Forestville
another 25 miles today, I think I need to get some earplugs. the vibration is a little much at some times, but it is getting me by no serious problems yet, it is I am still running 16:1, time to unleash full power with a leaner mix..
 
2door

2door

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I stand corrected...
When I first read this post by AJAGLASS, I read, "ground wire" and wrongfully interpreted it to mean the black wire, which is the ignition system ground wire. My advice was based on that. As the thread progressed and he insisted that he had soldered a wire to the core that came out of the coil, then had success, I got curious. I dug an old mag from my junk box and examined it carefully. I found a glob of soft, tar-like material on one corner of the core and when I cleaned it off with some solvent and a small blast from a bead blaster, sure enough, I found the wire he was talking about. Even more curious now I used my ohm meter and came up with this: White wire to core (ground)= 0 resistance. Blue wire to core= 340 ohms. Blue wire to white= 340 ohms. Knowing that this old coil had been oil soaked from a bad crankshaft seal, I went to a brand new motor that I'd just built and ohmed the coil...exactly the same as the junk one. The wire that AJAGLASS found and resoldered is apparently the other end of the white wire from the mag coil.
I've attached a photo; too bad I didn't take a picture before I cleaned off the goop hiding the solder joint in question.
You learn somnething every day. They say when that stops, you die. Glad I'm still learning. Thanks AJAGLASS.
Tom
 

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AJAGLASS

New Member
Mar 15, 2010
16
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Forestville
I was riding today, I thought I encountered the same magneto problem.. Suddenly, my bike died. I pulled the mag- cover, and inspected, poking with my screwdriver to see if connection was still intact. To my suprise, I did not see anything wrong with the Mag. Good thing I did not ruin it, while poking with my screwdriver, I could of broke the wire easy, and then there would not be enough to solder again.. To my suprise, I did not burn the mag. As I noticed the choke was very loose. So I put it back down, and it started. The cylinder was all full of mix, and it smoked for a bit.. after short ride, the choke is so loose now it will go up by itself.. So I took a rubber band, and wrapped it around the carb to hold it down. Problem solved, back on the road again. I must of put on like 60 miles since original fix.
 
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AJAGLASS

New Member
Mar 15, 2010
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Forestville
It finally burnt at the same point again, I don't know if there is enought to solder on again, the wire is all burnt looking, and I was wondering if this is common or if this happens to anybody else. I guess, I will order another mag, I wish they were a little more durable, maybe I just got a bad one. I just changed the plug, to a bp6hs, and it was going faster than ever. I put about 7 miles on after plug change, and it just cut out again. I probably put on like a hundred miles, in the last week, it was getting a little weak, and cut out once before, it finally died.
 
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AJAGLASS

New Member
Mar 15, 2010
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Forestville
dnutI managed to dig out enough wire to solder back on for the second time, i had to melt away the spool alittle more. I used a stronger solder iron this time and left a bigger solder blob on the contact, to hopefully dissapate a little heat from wire. I went ahead and tried it already, it fired right up, no problems. rode around the block once. I went ahead and ordered a new magneto, but I am not gonna install until I have problem, so i have a spare for the road.
 
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Kinnik

New Member
Jun 20, 2010
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Vancouver
Hi All! Just signed up to get some advise.. I love the bikes but I'm loosing faith.

I bought 2 80cc kits from 80cc Motor Boys and after sorting a slew of problems (parts missing, air leaks, gas coming out of air intake...) I finaly got both working nice and sweet when... I had my bike stop sparking. Same problem as AJAglass.

The TINY wire (as shown in 2Door's pic) connecting the coil to the 'top' side magnet broke. I was on a bumpyish road and going WOT... There was also the burn marks AJA descibed. Not sure if it broke from vibs then burnt from gapping sparks or just from heat?? Anyone have a guess? So, I found a friend that gave me a ride home (I was +50km from home ;P) Fixed by sodder.

So guess what... I was out again after several days of smooth sailing and I was going on the same dang road!! Yup, died again. But what was much worse... My GF's motor died too!! Almost the exact same time!! EXACT SAME PROBLEM!!! I 'almost' gave up on the whole MB thing. :( Luckly I brought a soddering iron with me and pluged in at an auto shop.. Got them both back up after ~ 1h of swearing and rode home... Only to have my bike die again, within pedeling distance. This time no amount of sodder would fix it. The wire is burried in the spoil and I think the sodder shorten the coil. No more sparks.

I will be getting three new magnetos on monday. Anyone have some ideas as to why this happened? Or ways to prevent it? Is it just NO bumpy riding (really it wasn't very bumpy, one rail road crossing but that was it)? Might I have it wired wrong? Could I reinforce that wire some how?? If so how?

Thank you very much for any help!! If you need any more info, I'll respond promptly.

BTW>> AJAglass, how is it going with your fix or your new mag?
 
G

goat88

New Member
Jun 11, 2010
7
0
0
kansas
AJAGLASS said:
.shft.Success, the bike is running stronger than ever. The only reason why I used only red, because that is all I had. The original wires were not soldered very well.. I did mark them, and I hooked up correctly.. To do with the little wire coming out of the side of the spool, I am sure that that was the problem. You can see pictures on internet of a new magneto, that has the same ground point soldered to body of c shape magneto next to spool on the blue side Good thing I know how to solder. Saved $$$$$ I have done this with no ohm meter, just by visual inspection.
Click to expand...
i know exactly what you are describing about that solder point being burnt, when my engine suddenly died a few days back i knew it was electrical, after trying many things i bought a new magneto, the old one was burnt at the same point, what he means is there is a small copper wire that comes out of the coil itself and is soldered to the metal forks that make contact with the magneto magnet in the engine, that had to be the problem because it was mine as well
 
Goat Herder

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
20
38
N.M.
Now get you some permatex silicone gasket maker [tuff stuff] Or some similar silicone use it as an anti vibration glue to keep those precious wires still and happy.:)
 
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