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Discussion Starter · #1 · (Edited)
Hi there,
So I picked up a Cb400t that hasn’t been registered for 9 years. Guy said he dumped it once because of the sticky drum brake and was too scared to drive it again. It doesn’t have a battery, so I attached an external 12v battery directly to the leads.
Electric start fires, but no spark. I checked it with the black/white wire unplugged, left side plug in the bike and the right plug grounded. I’ve already tested the ignition coil, moved onto the stator side I’m not getting the readings I want.
Green-Pink is open (exciter coil open?)
Brown-Light Blue is open (primary pickup Issue?)
Also I’m getting a resistance of 424ohms on my Green-Blue (following the FSM test) am I testing the green off the stator coming from the 6 point connector with the blue from the cdi power supply? Or is it a different green.
Otherwise, Blue-white is within spec, as is Green-Brown and Green-White.
Before I go searching for parts, could there be something I’m missing? Testing with the key off, black/white unhooked, cdi unplugged and direct testing to the 6 point connector on the frame. I’ve pulled off the rotor to look for any kind of damage but I can’t see anything. Disconnected the ground on the stator and made sure it was a clean connection. Is there something I’m missing?
308615
 

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Discussion Starter · #4 ·
I appreciate the help, sorry it’s been a while since responding. I’ve run some tests with two different multimeters and I keep getting different results, so I’m waiting on another one that isn’t a hand-me-down and will be more reliable to get the results I need. I feel like I shouldn’t post any results until this weekend when I have the new multimeter.
That being said, I’ve ordered two new spark plug ends cause they are definitely gone, thank you for that I definitely would have overlooked them.
It’s clear that I have power going to the CDI, and then for the ignition coil my primary is a little low at .2 while my secondary is within spec at 8.1k.
Like I said, I feel like I’m working with a couple faulty multimeters, so by this weekend I should have more reliable results, but as it is I’m not getting any readings on my green to pink and brown to light blue. It’s beeping on my green to pink at my highest setting but what it’s leading me to is a faulty stator and exciter coil? I’ve read through the forums and it looks like at the very least there are compatible stator and magneto assemblies until ~’85 for cb/cm 400-450s, so that’s been on my radar in the meantime. My worry is that I’m missing something simple. I’ve got the added difficulty of being away from my bike, so all the tests I do are about an hour away from home at my uncle’s shop. I’m a postie so I’m working crazy Christmas volume days, lesson learned, I did not know what I was getting into
 

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I understand the Christmas workload, my son-in-law works for Fedex and they're running the same type volume or more.
Any of the stators from 1978 thru 1986 CB/CM 400/450 engines fit and work. The CB450S stator will not work, Canada got that model in '87/88
 

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Discussion Starter · #6 ·
Well, I’ve got my stator out, bench tested it again (with my pulsar grounded to the stator) I’m getting an open circuit on my green to pink, and my brown to light blue is way out of spec.
I’m having no luck finding a stator assembly, even with branching out my search, other than an assembly for $350 plus shipping from the US and duty. It says it’s off a 82 cb450sc with the part number 31120-MC9-701, but I’m only coming across those on the ‘86 version of that bike. I think I’m to assume that’s part of the cb450s category that you mentioned isn’t compatible.
So I guess I’m hooped, until the point a stator appears.

I’ve called around to Bent Bikes in Langley, from what I hear that was my best option. Left an email with Super Sport with some part numbers. Scoured the depths of the internet. Now I’m trying to open up my search for places outside of the Lower Mainland. I don’t want to touch anything else on the bike until I get spark.
 

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The part number you list is the 1986 CB450SC but it will work fine for you. Any of the manual transmission stators for the 1978 thru 1986 CB/CM 400/450 series work.
The CB450S Has a different ignition system and that's why those won't work.
 

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I have a similar problem 79’ motor with 3500 miles on it. Was running fine then went to start it and no spark. All resistances at the stator check out besides the pink wire(Anything with the pink wire). It is not shorted to ground but has infinite resistance. I don’t have an M20 1.5 bolt yet but is there a Solder joint In there that might need to be repaired?
 

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I have a similar problem 79’ motor with 3500 miles on it. Was running fine then went to start it and no spark. All resistances at the stator check out besides the pink wire(Anything with the pink wire). It is not shorted to ground but has infinite resistance. I don’t have an M20 1.5 bolt yet but is there a Solder joint In there that might need to be repaired?
Also the GM coil is still sitting at 0.7resistance!
 

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You'll need to pull the rotor and stator to inspect the Pink wire completely, it's possible there's a break that can be repaired. The oil filter bolt is the correct size for rotor removal BUT you need to be careful not to round off the nut end of it. Most rotors are pretty well stuck in place. Do Not hit it with a hammer! Motion Pro sells the rotor puller bolt and you can find it on Amazon.
The .7 primary resistance of the GM coil is good.
 

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You'll need to pull the rotor and stator to inspect the Pink wire completely, it's possible there's a break that can be repaired. The oil filter bolt is the correct size for rotor removal BUT you need to be careful not to round off the nut end of it. Most rotors are pretty well stuck in place. Do Not hit it with a hammer! Motion Pro sells the rotor puller bolt and you can find it on Amazon.
The .7 primary resistance of the GM coil is good.
Thanks Jim, just got the bolt today and will pull and inspect later. The pink wire is for the advance pickup, if the advance pickup is the only thing not in spec, wouldn’t you still get spark with only the other trigger coil working? I hope not as that means it maybe took out the CDI as well?
we will see.
 

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The primary only should give you spark but it may be erratic. CDI's are always suspect since we don't have any valid tests for them.
 

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The primary only should give you spark but it may be erratic. CDI's are always suspect since we don't have any valid tests for them.
Well bummer I zipped off the rotor with an impact gun. Couldn’t find a good way to hold it while turning the bolt. Checked the pink wire right at the advance pickup and it has continuity all the way back to the connector. So no broken connectors. So I need at least an advance pickup and possibly a CDI. Doesn’t look like they are available. Has anybody tried to rebuild one before?
 

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Thanks Jim, now considering an Ignitech CDI as well. Looks like repairing the stator is going to be expensive. At least $300 with the cdi unit. It seems like I can at least use my broken stator with the Ignitech unit. Eventually maybe do what you have done to your bike, the GL1000 stators seem plentiful and cheap on eBay. If I do end up going the Ignitech route would it be possible to use a coil
like the IP6 here?

I would want to order one as a backup if the original coil goes out.
I know a mounting bracket would need to be fabricated. But functionally do you think it would work? I looked on the forums and didn’t see anything.


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It's possible to use one of Jeri's pickups. I would contact him and ask which one plus any advice on placement/mounting/etc.
I've wondered about using one of them as a replacement with the stock CDI but haven't had the time to work with it. Plus the only candidate I have to play with is my kickstart only T1.
 

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I contacted Jeri and he said that no his pickups will not work. The pickup on our bike has two coils. I am waiting on a quote from him. As the coil needed is working on my stator. At this point I am seriously considering going with the Ignitech unit. I sent an email to rick’s Motorsport they offer the option to rebuild both pickups but it has to be in addition to a full stator rebuild. They claim it is very labor intensive to rebuild the coils. It is a bummer because this motor hasn’t even seen its first 3750 mile service. The stator looks brand new. The motor and CDI and cluster sat stored indoors since 1979. Only 52 miles were ever put on the original bike. It now is at 3569 with the miles I have put on it. I will keep an eye out for a burned up stator. I would like to see how hard it is to rebuild and pot these coils yourself.


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I contacted Jeri and he said that no his pickups will not work. The pickup on our bike has two coils. I am waiting on a quote from him. As the coil needed is working on my stator. At this point I am seriously considering going with the Ignitech unit. I sent an email to rick’s Motorsport they offer the option to rebuild both pickups but it has to be in addition to a full stator rebuild. They claim it is very labor intensive to rebuild the coils. It is a bummer because this motor hasn’t even seen its first 3750 mile service. The stator looks brand new. The motor and CDI and cluster sat stored indoors since 1979. Only 52 miles were ever put on the original bike. It now is at 3569 with the miles I have put on it. I will keep an eye out for a burned up stator. I would like to see how hard it is to rebuild and pot these coils yourself.


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I contacted Jeri and he said that no his pickups will not work. The pickup on our bike has two coils. I am waiting on a quote from him. As the coil needed is working on my stator. At this point I am seriously considering going with the Ignitech unit. I sent an email to rick’s Motorsport they offer the option to rebuild both pickups but it has to be in addition to a full stator rebuild. They claim it is very labor intensive to rebuild the coils. It is a bummer because this motor hasn’t even seen its first 3750 mile service. The stator looks brand new. The motor and CDI and cluster sat stored indoors since 1979. Only 52 miles were ever put on the original bike. It now is at 3569 with the miles I have put on it. I will keep an eye out for a burned up stator. I would like to see how hard it is to rebuild and pot these coils yourself.


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Well I ended up going with the Ignitech unit. I have some carb or timing issues now. I need to get the unit connected to a computer and check that the timing settings are programmed correctly. The bike has a flat spot off idle if the choke is not partially open, makes me think it is carb not timing related. It could be a vacuum leak somewhere as well. It sat for quite a while after it wouldn’t start. The bike now starts instantly and idles very smoothly. I swear it sounds different! Anything above 1/4 throttle, or if I operate the throttle smoothly, the bike runs just great. I drove it 100 miles the first day I got it running again. So far I am very pleased with the ignitech. It was a bit slow to ship once ordered, but shipping time was fast. Three days from Czech Republic to my door.
 

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Discussion Starter · #20 · (Edited)
Well, I did it, I bought the stator, worked 6 days weeks for the last couple months, got a flu that was like covid but wasn’t covid, and on my 14 day quarantine I’ve finally been able to put it in. It’s testing at all the resistances it should. Went through and did the carbs and set up an in-line filter. BAM it’s running!
Thank you so, so much for your help.
Next plan of action:
Oil change
Valve set
Check timing
New plugs
Tackle the front brake
New tires

After that it’s cosmetic stuff. Changing the seat, lowering the headlight, new bars, swapping the signals and fenders.
Very stoked!
 
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