Flooded Magneto, Need Help

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Will122391

New Member
May 31, 2013
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Texas
I went to start the bike yesterday and found it had no spark. I have recently soldered the wires up so I wouldn't have electrical problems........ Anyway so I opened up the magneto area. Does the magneto look like it is in good shape? I have no idea what to look for here. I don't have a multimeter and I'd rather be able to eyeball it.

 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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memphis Tn
You cannot tell by looking if the coil is shorted.
Has there been water in that case? It looks like it has rust from water. If so, water is death to these coils. Get it wet and it WILL fail.
This may have killed yours.
 

Will122391

New Member
May 31, 2013
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Texas
You cannot tell by looking if the coil is shorted.
Has there been water in that case? It looks like it has rust from water. If so, water is death to these coils. Get it wet and it WILL fail.
This may have killed yours.
The bike is normally stored outside and has never had electrical issues before, but it did rain very hard recently so that may have ruined it. If I order a new magneto, is swapping them out as simple as unbolting the old one and bolting on a new one?
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Swapping magneto coils is indeed just that simple. Remove the four screws, remove the coil and replace it with the new one. Some will suggest you scrape the varnish coating from the back of the coil so you have a good electrical ground to the engine case. Also where the black wire, the ground, attaches to the coil is a suspect area where you want a good connection.

Tom
 

BigBlue

Member
Nov 29, 2011
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California
Also might want to seal the cover and where the wires come into the case with some high temperature RTV silicone. It will help keep water out of the case.

And also wrapped some black electrical tape around those soldered connections. Shrink wrapping would be a better alternative.

When you can, try and purchase a DMM at Harbor Freight for under $10.00 on sale. Sometimes you can get them for free.

Good Luck,

Chris
AKA: BigBlue
 
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Kioshk

Active Member
Oct 21, 2012
1,152
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Connecticut
"Short" of buying a DMM, you can verify magneto-coil/CDI operation by removing your spark-plug, reconnecting it to the CDI wire, holding the plug's thread-end against the head, and rolling your bike forward with the clutch disengaged. You should see (and maybe even hear) a spark in the gap if all is good. It's also a good habit to always have a reserve coil on hand.
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
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Littleton, Colorado
"Short" of buying a DMM, you can verify magneto-coil/CDI operation by removing your spark-plug, reconnecting it to the CDI wire, holding the plug's thread-end against the head, and rolling your bike forward with the clutch disengaged. You should see (and maybe even hear) a spark in the gap if all is good. It's also a good habit to always have a reserve coil on hand.
I think you want the clutch 'engaged' for this test. :)

Tom
 

Will122391

New Member
May 31, 2013
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Texas
Yea I did a plug test when I took it apart and had no spark whereas I had done this before and seen spark just months ago. Looks like I'll be ordering a new magneto. I'll follow up once I get it.
 

Kioshk

Active Member
Oct 21, 2012
1,152
10
38
Connecticut
Yea I did a plug test when I took it apart and had no spark whereas I had done this before and seen spark just months ago. Looks like I'll be ordering a new magneto. I'll follow up once I get it.
Whelp, I think you jinxed me. It's rainy here in New York, and I left my bike out last-night. I rode about 2-miles then my coil died. I always carry a fresh one in my kit, so I was back on the road in no time. That magneto lasted me about 3-months of heavy use. I never got around to properly waterproof it though, and paid for it. I now only have ONE fresh spare, so I shall order another tonight.

BUY TWO!
 

Will122391

New Member
May 31, 2013
90
0
0
Texas
Whelp, I think you jinxed me. It's rainy here in New York, and I left my bike out last-night. I rode about 2-miles then my coil died. I always carry a fresh one in my kit, so I was back on the road in no time. That magneto lasted me about 3-months of heavy use. I never got around to properly waterproof it though, and paid for it. I now only have ONE fresh spare, so I shall order another tonight.

BUY TWO!
Ha I was just thinking of getting an extra for later. You make it sound like magnetos are an annoying problem, but an easy fix. How do you go about waterproofing your case?

Also, I was examining this picture and I realised a stud has fallen out at the cylinder base! I'm afraid to pull out the other one to find the specs of the stud so does anyone happen to know them off hand?
 
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2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Replace it with a 6mm X 1 thread, 40mm in length. Go with Allen head capscrews instead or the original screw head type fastener.

Tom
 

Will122391

New Member
May 31, 2013
90
0
0
Texas
I installed the new magneto today and suddenly the engine was producing a spark again. I installed the missing bolt and used gasket sealant to help waterproof the case. Then i fired up the bike and it ran great dnut