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i have an old 1980 honda bike i picked up that has a cdi system and no spark. there are 2 suspects in this: the cdi unit itself or the magnetic pickup that tells the cdi when to fire. there is a testing procedure and the only fault ive found is that the pickup coil is 60 ohms under spec (147 instead of 207) so it may not be making enough of a signal for the cdi to see and spark. there is no testing procedure for the cdi box because 80s japanese space magic, the only way to test it is to eliminate everything else. ideally i would just replace the pickup and try again, but for some fucking honda decided to integrate it with the stator harness and only sold it as an assembly so now there are very few parts floating around and they are very very expensive. so i basically have 3 options:
>buy a new stator assembly and hope the cdi box is good, if not spend even more on that
>buy a used cdi box and hope it works or get disappointed and left with another working $150 part
>build an amp for the trigger
>make my own ignition system
i got the bike for $100 and its in rough but complete shape, so im really not about to go spend 6x the value of the bike on 1 or 2 parts. number 3 seems feasible but i dont know how i would go about that or if it would even work since no one knows how the cdi even reads the signal, so boosting it might not even have an effect. im really leaning towards number 4 because a 12 year old can follow transistorized ignition plans online, really the only issue i think i will have to work out is how i will trigger it because i have no idea how to do that with a magnetic pickup system. it would just need to react to the pickup firing to cut the transistor thats powering the coil to induce a spark, and it would need to be fast enough to work up to 10k times a minute (10k rpm redline).
can anyone give me some guidance on how to accomplish something like this?
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grow a pair, you don't need a manual to tell you what a fucking magnet passing a fucking coil does.
the signal is a pulse, typically more than half a volt but less than twelve.
set your multimeter to ohms, ground one probe, poke the CDI sense pin with the other probe, observe the spark at the plug.
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>>1198236
If you're getting less coil resistance than expected, the windings are shorted. Epoxy breaks down, vibration knocks shit apart, temperature fatigues the materials.
What i'd do ... buy a spool of magnet wire, carefully unwind and note which direction the windings go (That may be a 3-phase coil, so you'll have 3 wires/6 ends to deal with, and probably another for ignition). Wear gloves when you unwind it, the old wire is like handling razor wire.
Then rewind the coils.
CDI module is kind of hard to bench-test without equipment. I'd start with the easy stuff like the coil first, then if that still doesn't work, replace the CDI.
Something that old, you'll probably want to rework the stator coil anyways just for reliability even if that's not the issue.
Ohm out the wiring harness too.
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Honda's have two main areas of weakness... The reg/rec, and stator. When one fails, it takes the other one out. Both are cheap and dead easy to replace, so any issues relating to ignition and charging should be followed by changing both of those. I strongly recommend not using the three pin connector between the stator and reg/rec and make your own loom.
Reg/recs fail in one of two ways: the diodes fail and you get no output, or the shunt fails and the DC output is no longer regulated, meaning too many volts. Check for any signs of battery acid leakage, because all that extra voltage boils the battery and can cause utter havoc with the electronics.
Good luck.
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>>1198236
Cdi is blown. Replace.
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>>1198236
Just replace the parts. Its most likely that if they work now they will fail later. Old honda cb's are almost bullet proof besides the electronics.
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>>1198261
no dice on this one. i did each pin with a probe on ground and inbetween both pins and nothing. also tried it while cranking.
>>1198331
the unit is the silver part on the right side of the op pic, not in the stator itself which is why there is no reason for honda to not sell it separately. stator all checked out in spec as well. if i can get this cunt running and going reliably, then ill do the new vintage bike maintenance. until then i just want to get to fuckin start.
>>1198337
according to the schematic the cdi is powered directly by ac from the stator and the stator is good. the cdi does output 10 volts to the coil when cranking, but it does not modulate its just a constant 10v telling me that its waiting for the signal to break the connection and induce a spark but its not able to sense it. battery looks fine too, physically at least aside from the rusty terminals. only got 10 millivolts but i guess that happens when its been chillin outside untouched for 20 years.
>>1198353
im not in the position to throw a lot of money at this bike at the moment so i would like to be absolutely sure it really is dead. given the fact that the pickup is suspect that is the route i would like to pursue.
>>1198395
>just replace the parts he says
several hundred dollars, if you can even find it. dont want to blow that much on a shitty old bike even if i had the cash to spare. also its a cm400 not a cb which is probably why parts have completely dried up with no aftermarket.
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>>1198236
If you replace any parts. Replace them with non OEM stuff. Japanese bikes electronics are garbage. And actually its not limited to jap bikes. Italian, British, American all use the same shitty electronics..
Test the ignition coils. They commonly go out on Honda's and Suzukis. From the 1980s all the way to 2009.
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>>1198478
trust me, if i can find some aftermarket shit i would use it but its always the dollar parts like ignition coils and regulators, not the actual shit like stators and ignition modules.
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>>1198480
Bikebandit.com sells generic stators and ignition modules.. Also there's this cafe racer dedicated website that I forget the name too but just search for something like it. But it carry's stuff for like all the CBs. 125s to 750s.
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here is the official unofficial testing procedure to eliminate all other possibilities down to the cdi
>Coil Test:
>Primary Side- Spec is .35 to .55 ohms
good
>Secondary Side- Spec is 7.2K ohms to 8.8K ohms
good
>Plug End Caps- Spec is 5K ohms
good
>Stator Tests:
>Measure the resistance of the Pink and Green wires. This is the advancer pickup sensor
>The resistance should be about 135 Ohms
good
>Measure the resistance between the White and Blue wires. This is the CDI power source
>The resistance should be about 85 Ohms
good
>Measure the resistance between the Brown and Light blue wires. This is the primary pickup coil, the aluminum piece outside the rotor
>The resistance should be about 207 ohms
low, 147
>Run/Kill and Ignition switch Tests:
>Ignition switch on, Run/Kill switch in Run position: Infinite Ohms
good
>Ignition switch on, Run/Kill switch in Off position: Zero ohms
good
>Ignition switch OFF, Run/Kill in any position: Zero ohms
good
>Alternator Tests:
>Connect the other probe to one of the remaining 2 Yellow wires, resistance should be below 1 ohm. Repeat twice using a different wire each time
good
>Test each of the Yellow wires with one probe connected to ground. There should be an Infinite ohms
good
also included a schematic with the wires traced in color. every line is directly attached to the stator with the only exception being the black and white line (traced in red) which is the grounder for shutting down the bike and only completes to ground with the e stop on or the ignition off.
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>>1198482
checked them out, they have jack and shit for it i cant find on ebay for 1/3 the cost.
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>>1198486
Wow. Not listening to anything anyone has said. Nobody is gonna spoon feed you. Gtfo.
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>>1198489
>this website sells what you need
>doesnt sell what i need
>done everything i can to diagnose the bike and want opinions and insight
>hurr not gonna spoonfeed you
neck yourself you dumb cunt
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