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Discussion Starter · #1 ·
My 1981 cm400c will crank but won’t start. I get a weak spark or no spark.
I’ve been lurking here for days and finding lots of good info, but still no spark.

Here’s some of the readings I’ve gathered:

Coil primary 0.7
Coil secondary 7.29k
Plug caps 5k
Advancer pickup 110
Cdi power source 77
Primary pickup 190
3 yellow wires .8, 1, 1 ,none grounded

Thanks in advance for your excellent advice!
 

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Discussion Starter · #2 ·
I also tried a gm coil mod, but nothing changed. I have both the gm coil and the original coil, the numbers above refer to the original coil.
 

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I know this may look obvious but have you checked your battery? A good battery should be 12.6V at rest. Anything less would be suspect.
 

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Discussion Starter · #6 ·
I’ve been using that ignition diagnosis information and I posted my readings but I’m still not sure what parts are bad.
 

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Discussion Starter · #7 ·
My stator readings are not to spec but I don’t know how to interpret the results.
 

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Put a meter set on voltage connect the blue wire and the white coming from your stator crank motor over it should be 10 volts or over, If not bad stator.
 

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Discussion Starter · #9 ·
Bummer. I only get 3 volts from the blue and white stator wires while cranking.
Is that a clear diagnosis of a bad stator?
 

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Sounds like a dead stator. I changed one awhile back that was bad it put out 4 volts.
 

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Discussion Starter · #13 ·
A nice guy on this forum is going to sell me a used stator for a very fair price. I think I’ll have it in a few days. Meanwhile, I set out to pull my stator for replacement.
I’ve got the bolt off that holds the rotor, but I don’t have a flywheel puller. What tool is it that I need to pull my rotor? Can I use an automotive flywheel puller; I could maybe borrow one from a friend? I’ve heard that AutoZone loans out flywheel pullers.
 

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Discussion Starter · #15 ·
A nice guy on this forum is going to sell me a used stator for a very fair price. I think I’ll have it in a few days. Meanwhile, I set out to pull my stator for replacement.
I’ve got the bolt off that holds the rotor, but I don’t have a flywheel puller. What tool is it that I need to pull my rotor? Can I use an automotive flywheel puller; I could maybe borrow one from a friend? I’ve heard that AutoZone loans out flywheel pullers.
Sorry to waste your time. I found a thread here discussing rotor pulling. It’s annoying to pay $15 for a bolt, but I can’t find anyone locally to sell me a 20mm bolt with a 1.5 pitch thread. I guess I’ll order one from motion pro.
 

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The one in my link above is $10.54
 

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Discussion Starter · #19 ·
I need help. Can someone please hold my hand and help me get a spark?
I just installed a used stator (thanks HamHock!) that came off of a running bike. Here are the ohm readings that I took just now:
Coil, primary .7
Coil, secondary 7.32k
Plug end caps (new) 4.86k and 5.08k
Pink and green advancer pickup 127.4
White and blue cdi power 77
Brown and light blue primary pickup 197

I really don’t know what I’m doing. Can you help me interpret these results?
 

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I need help. Can someone please hold my hand and help me get a spark?
I just installed a used stator (thanks HamHock!) that came off of a running bike. Here are the ohm readings that I took just now:
Pink and green advancer pickup 127.4
White and blue cdi power 77
Brown and light blue primary pickup 197
The stator readings are all low. I would replace the battery in your VOM and retest first. You want the ohm readings to match up with the specs listed in the Ignition Diagnosis http://www.hondatwins.net/forums/64...0-450-cb450sc-manual-trans-1978-1986-a-2.html
Coil specs are ok.
 
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