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- 11:29 PM
- Mar 31, 2021
I have seen it said that with a cdi that has the coil built into it , it will show a reading of 6-8 between the black and blue wire if it is good --- all 3 of these catnips ( or clones maybe ) show nothing any way you connect the leads , even chainlube's methodYou can't read a cdi like that. They are a capacitive circuit. Every time you apply the leads you are charging the capacitor if any current is flowing, and the cdi is waiting for an opposing wave to trigger. You can test the coil, but the cdi can't be tested that way. You just have to hook it up and see if it sparks. You should get a white, blue or purple spark. A yellow spark is weak. Is your plug bad?
Ohm the magneto from the black and blue wire, 320-380 ohms is ideal, an open or dead short means a bad magneto if the wires are connected.
Ohm the CDI in the 10K-20K scale.
Red+ meter probe to CDI black wire.
Black- meter probe to the spark plug cap.
You should get about 6.9K ohms.
That's some good links , lot of info , but didn't see any stand alone coil set upsI do not know about the catnip magneto and CDI but on my stock china girl you can use a ohm meter to check both.
The above is copy pasted from
There are several posts on this forum regarding checking both with an ohm meter.
I also check mine with all the wires disconnected from each other when I check the CDI I disconnect the spark plug wire and test it from the screw that holds the wire on (black negative on the OHM meter and the red positive to the black input wire)
but didn't see any stand alone coil set ups
The coil is a separate of the cdi and when I test the cdi separate alone , all three they test bad
My cat nips ones have thousands of miles on them. They are a copy of the thunder cdi, or the curve is pretty dang close to it. I actually havent had a single failure with a catnip cdi. I even weld on my bikes with it still hooked up because i usually forget to disconnect it. Stock cdi are good too, best power from stock cdi ive seen so far. Im currently researching an adjustable electronic cdi setup. I'll figure one out eventually. Just time constrained. When i do ill make a post on how to build it.We had a hurricane come thru , lost power and internet for 11 days so did not get much done on the bike project ----- still got no fire/spark
Looking to buy the complete cdi , magneto , magnet set up , what's is the best most dependable one out there