Multimeter to test magneto/coil

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it would have to be really bad to affect it. depends on the tightness of the spark plug mostly. I clean that area when I remove the spark plug. better safe than sorry
 
the real causes of ignition failures

Here is why you have failing parts in the ignition .
Some of the Chinese manuals show to incorporate the white wire into the ignition system.
the white wire should be cut off and thrown away. it is a generator line only! not an ignition wire. It will wipe out the cdi and sometimes it wipes out the mag too.

also....the blue wire is the HOT.... the black is ground and is usually screwed onto the magneto frame
use the black to the engine block for ground
the only wire needed on the mag is the blue wire!
you can remove the white wire and instead of the black going to the mag frame and route the black from the coil to any good ground point on the bike
the only connection that HAS to go into the mag is blue to blue. Your kill switch just has to break the blue wire . Keep the black as ground.

Here is a primer on how to electrically test you magneto and cdi.

Disconnect the kill button to make sure it is not giving you a no spark condition. Some are defective. Make sure the plug wire is screwed securely into the CDI and you have a good connection at the plug boot, the plastic part that snaps onto the plug. If you've already done these things and have access to a good ohm meter check your ignition components against the numbers I've attached. Get back to us with the results.
Magneto

Use Low Ohm-Meter Scale About 200 Ohms

1) Check Ohms between BLACK wire and WHITE wire. Reading should be around 2 Ohms

2) Check ohms between BLUE wire and WHITE wire. Should be around 300-400 ohms.

CDI

Use Ohm Meter High Scale About 200-K

1) Positive lead on BLUE wire and Negative lead on BLACK wire should read infinite (no activity)

2) Positive lead on BLACK wire and Negative lead on BLUE wire. Should be about 130-150 K-ohms

3) Positive lead on Spark Plug wire and negative lead on BLUE wire. Should read between 135-155 K-ohms

Switch to Low Scale 20K

4) Measure between Spark Plug wire and and Black lead. Should be about 2.5 - 2.7 K- ohms
 
I actualy just took the whole wiring set up apart. there was a white wire connected to the lower of the magneto coil but it wasnt connected at the other end. my kill switch was in between black and blue. now though, i have the kill switch totally un attached. Its just simply blue cdi to magneto, and black cdi to magneto frame ground. first thing i did when i got the bike was cut the ****ty boot off, strip the wire rubber and wind the copper cable directly around the spark plug and secure it into to nuts. so thats all good. I have replaced 3 magneto coils in a month scince getting the bike though. i took the magnet rotor off and it seems that the seal behind it could possibly be leaking a slight amount of oil when i got for long WOT rides.. which could be whats killing my magneto coil over and over? either that or the kill switch was? im seriously confused on how my coil dies so often.
 
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now im :unsure: even harder....

your using no boot at all? straight onto the plugs thread?

hmm, very similar to my boot which is just a spring speared into the wire...

no resistor.

neither is the plug.

what plug are you using? b5 or br5?

this may be the reason to be using a boot and or plug with a resistor...

ive only been having issues really since using this "spring boot"...


just thinking... unquenched back emf...iunno...maybe...




hmmmms. a plugs a cheap experiment...
 
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now im :unsure: even harder....

your using no boot at all? straight onto the plugs thread?

hmm, very similar to my boot which is just a spring speared into the wire...

no resistor.

neither is the plug.

what plug are you using? b5 or br5?

this may be the reason to be using a boot and or plug with a resistor...

ive only been having issues really since using this "spring boot"...


just thinking... unquenched back emf...iunno...maybe...




hmmmms. a plugs a cheap experiment...
yeah i just took the wire from the cdi wraped it around the spark plug thread. i have 2 nuts that fit the sparkplug thread and the wires in between them and secure. and tapped too of course.

im not sure which plug it is.. just the one it came with i presume (stock).

my magneto isnt killing itself. tomorrow im going into the city to zoombicycles warehouse and im going to get a new cdi, magneto and probably the crank shaft seal that fits behind the magnet rotor as mine leaks small amounts of oil into my magneto area. cdi and magneto are 15 bucks each no taxes and the rubber seal is 2 dollars. cant really go wrong right?

depending on how that goes i may even buy an expansion chamber exhaust as i hear it really makes a performance difference.. maybe even a better carb as mine leaks a bit of oil. i checked my magneto with a multi meter and it reads .002 ohms from white to black which is right on the 2k ohm setting. but then blue to white wire has no reading so i think its fried. oh well
 
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i read "stock chinese plug"

"purchase new cdi n magneto"

something about a seal...

and not one mention of getting a new plug! or a real ngk boot with a 5k resistor from a motorbike....

bah humbug. last time i think for someone :eek:

(the bpr6hs has stopped my speedo playing up from the interference too)
 
ill get a plug too but should i get one from zoombicycles? itll probably be another chinese HT one. the new cdi im getting from zoombicycles also comes with a boot.
 
Magneto protection

yeah i just took the wire from the cdi wraped it around the spark plug thread. i have 2 nuts that fit the sparkplug thread and the wires in between them and secure. and tapped too of course.

im not sure which plug it is.. just the one it came with i presume (stock).

my magneto isnt killing itself. tomorrow im going into the city to zoombicycles warehouse and im going to get a new cdi, magneto and probably the crank shaft seal that fits behind the magnet rotor as mine leaks small amounts of oil into my magneto area. cdi and magneto are 15 bucks each no taxes and the rubber seal is 2 dollars. cant really go wrong right?

depending on how that goes i may even buy an expansion chamber exhaust as i hear it really makes a performance difference.. maybe even a better carb as mine leaks a bit of oil. i checked my magneto with a multi meter and it reads .002 ohms from white to black which is right on the 2k ohm setting. but then blue to white wire has no reading so i think its fried. oh well[/QUOTE


Another good thing is to dip connections into wax or fingernail polish. make sure to clean area to be grounded.
 
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