Still no spark, despite new plug/magneto/cdi

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gaboo

New Member
Sep 3, 2012
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uk
Any suggestions anyone? Have now bought all new parts, and all of them get the correct readings on a multimeter, but I still get no spark on my bike. I have read most of the guides on here and several threads, but can't think of anything else to do.
 

Greg58

Well-Known Member
May 1, 2011
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Newnan,Georgia
Have you checked the key under the magnet? If the key is sheared it may be firing but out of time. Remove the spark plug reconnect it to the cdi and hold the plug on the head and roll the bike watching for spark as the engine turns over. If the key is good and you see the plug firing check your compression.
 

BigBlue

Member
Nov 29, 2011
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California
Did you replace to spark plug wire? Check for solid solder connections? What kind of plug did you replace it with? Chinese or NGK?

Good Luck,

Chris
AKA: BigBlue
 

Greg58

Well-Known Member
May 1, 2011
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Chris he said he has replaced coil, cdi and plug so I was looking for another reason for his problem. I know the quality of the wire is questionable but since he has tried two it may be elsewhere.
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Tell us how you have it wired.

Correct: Blue wire from engine to blue from CDI. Black from engine to black from CDI.
White wire isolated and NOT connected to anything and not touching any metal.

Kill switch wires spliced into the blue and black wire connections?

Factory supplied bullet or push on connectors disgarded and the connection soldered?

How are you checking for spark and what is plug gap?

Tom
 

BigBlue

Member
Nov 29, 2011
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California
OP didn't say he replaced the spark plug wire or checked for resistance.

Still need to check the spark plug wire or replace with a good quality one. It may be cracked/broken or even unscrewed from the CDI unit.

Which magneto did you replace the old one with. There are two type of magnetos. What was your readings on the magneto?

Here's some important info. on magnetos from Grubee:
http://www.grubeeinc.com/USA/Magneto Mystery.html

Chris
AKA: BigBlue
 

gaboo

New Member
Sep 3, 2012
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uk
Thanks for the help so far guys, I have limted knowledge but will try to answer the questions. I know the readings were correct i checked them with bikeberry's video on setting up the electronics.
I check for spark by attaching the sparkplug to the cdi, connecting the black cdi to black engine, and blue to blue, then isolating the white wire. I pull the clutch lever when doing this so the wheel can turn freely, not sure if this is correct to do.
The kill switch is always disconnected.
I have already unscrewed the thick wire on the cdi and stripped some of it, then reconnected it.
Not sure what the key under the magnet is, how do I check that?
The magnetos are both old models, but the guy i bought a replacement off is sending me a new one so i guess I can try that, but surely if the readings are correct it is working?
 

Greg58

Well-Known Member
May 1, 2011
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You need to let the clutch out to turn over the engine, with the plug out of the engine it will turn freely. The key is under the magnet on the left side of the engine, where the blue black and white wire come out of the engine. If you replaced the coil it was under that cover.
 

gaboo

New Member
Sep 3, 2012
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uk
If the clutch is let out, then surely i won't be able to spin the wheel on the bike?
 

gaboo

New Member
Sep 3, 2012
5
0
0
uk
Solved, it was a combination of small problems. The magneto wasn't fitted in perfectly, and the motor didn't spin properly. I also flooded the engine with petrol, after trying so many times to start it + I used a 16:1 ratio which I think was too lean.
Thanks for the help guys, I'm not really an enthusiast but if there's any way I can help give something back I will.