Testing the CDI.

JoeBar

New Member
Joined
Jun 13, 2021
Messages
5
I have an 80cc motor with the common no start no spark. I've heard of testing them with the multi meter and several opinions on how to do it. So on the bike, I tried black to blue wire and get no change so then I tried black lead in the plug boot clip for the plug and red lead to the black and then to the red and still no change. I've been riding for years, and have always used the process of elimination. So I have 3 brand new ones In the package still. I tried both ways they say to ohm it and get no change with any of the methods I described. I would be ok if it was just one. But 4? 3 brand new ones and the one on the bike???.......
 

JoeBar

New Member
Joined
Jun 13, 2021
Messages
5
I get a reading on a new CDI when I go from black to plug.
You say black to plug, is this with it still on the bike and your touching the plug itself. I dont think the 2 brand new ones, my new one on the bike and the one I just took off, I get no reading. I put the black inside the boot or the attachment screw on the cdi and red to biack wire end and I don't get anything but I can ohm test the stairs and get readings? What am I doing wrong here,
 

JoeBar

New Member
Joined
Jun 13, 2021
Messages
5
You say black to plug, is this with it still on the bike and your touching the plug itself. I dont think the 2 brand new ones, my new one on the bike and the one I just took off, I get no reading. I put the black inside the boot or the attachment screw on the cdi and red to biack wire end and I don't get anything but I can ohm test the stairs and get readings? What am I doing wrong here,
Stators
 

Chainlube

Well-Known Member
Joined
Jan 5, 2020
Messages
4,005
It is a little hard to make contact with the plug wire inside the boot, my probe is a little short. I really have to force it in there to make contact.
I set it at 20K, but I'm not much of an electrical guy.
 

Bigdog motorized

New Member
Joined
Sep 11, 2021
Messages
2
I have an 80cc motor with the common no start no spark. I've heard of testing them with the multi meter and several opinions on how to do it. So on the bike, I tried black to blue wire and get no change so then I tried black lead in the plug boot clip for the plug and red lead to the black and then to the red and still no change. I've been riding for years, and have always used the process of elimination. So I have 3 brand new ones In the package still. I tried both ways they say to ohm it and get no change with any of the methods I described. I would be ok if it was just one. But 4? 3 brand new ones and the one on the bike???.......
Have you checked the magneto because it could be the problem cause the magneto should read 327-345 ohms try that and if it is not that most likely it’ll be your cdi or spark plug
 
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