Intermittent spark

Dodgy Kips motor? CDI? battery? diode? reg/rect? its all gobbledygook to me but some people understand it ask tham a question here
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glidercoach
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Post by glidercoach »

Stator swap failed! I did find something interesting. I'll have strong spark on both cylinders for a dozen kicks, then nothing. When I unplug the front CDI unit, spark returns (to the rear only of course!) When I plug it back in, nothing. After a few minutes, spark returns to both but soon fails to both. When I unplug the CDI unit, spark returns. If I unplug the rear, the front still has no spark! Please advise of my next move, test or fix! I have no spare CDI units!!! Can the CDI units be repaired? I'm almost there guys... HELP!
:-k
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ScottaKR
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Post by ScottaKR »

Try pluging the CDI that fires the rear spark (RHS from memory), in to fire the front CDI. If you get spark to the front consistantly, then it's safe to say that the problem is definately the CDI and you can replace it.
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KR1S Track Bike (has been put on hold for now)
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glidercoach
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Post by glidercoach »

The front CDI unit in fact was affecting both cylinders! now I need to find one or both would be better. Please assist me guys! How does a person find a working CDI? Can, should I insist on a guarantee when buying one on ebay or where ever?
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ScottaKR
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Post by ScottaKR »

I wish I could help out with a spare CDI, but since my Tandem Twin isn't running right now, I can't test my spare CDI units. You could always go for an after-market programable CDI system. :-k
KR250 Tandem Twin (Naked) :mrgreen:
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KR1S Track Bike (has been put on hold for now)
ZXR750 H1 (Winter project)
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glidercoach
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Post by glidercoach »

Update! While waiting for a spare CDI unit, I took apart the bad one. Wow it was tough to take apart without destroying it. About 20 hours to remove the gravel/silicone potting material. I found a poorly soldered component. Resoldered it, plugged it in and she fired right up! I thought I was wasting my time opening up the unit, but it worked. I need to make a waterproof box as I destroyed the original. It is possible to repair a CDI!


\:D/
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Howie
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Post by Howie »

Full marks on that one glidercoach =D> But i think you've found the reason no one wants to repair one or pay some one to repair it, 20 hours!

I admire your patience sir
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smithyrc30
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Post by smithyrc30 »

The potting compound that Kawasaki (and most of the other bike makes use) is an epoxy based material.

This stuff is dissolved by Ethanol, it goes all soft and breaks up really easily. If you are careful with it, you can get it all off without damaging anything.

I used to modify the CDI boxes on the AR50's and the like for local nutters. A couple of hours in that and a some soldering and the retarded ignition curve was gone and instant speed increase to 45mph!!!!

If you put on the AR80 carb and chucked out the head gasket they would do nearly 50mph. The carb mod was 'big bucks' back in them days though.....
GEN1S1S

Post by GEN1S1S »

smithyrc30 wrote:The potting compound that Kawasaki (and most of the other bike makes use) is an epoxy based material.

This stuff is dissolved by Ethanol, it goes all soft and breaks up really easily. If you are careful with it, you can get it all off without damaging anything.

I used to modify the CDI boxes on the AR50's and the like for local nutters. A couple of hours in that and a some soldering and the retarded ignition curve was gone and instant speed increase to 45mph!!!!

If you put on the AR80 carb and chucked out the head gasket they would do nearly 50mph. The carb mod was 'big bucks' back in them days though.....
Can you let me know what to do in the AR CDI to remove the 7k limiter and retarder?
Be very helpful and save a lot of cash!!!
Thanks
Lloyd
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smithyrc30
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Post by smithyrc30 »

Oooh, now I'll have to think about that....

It was twenty plus years ago when I did the first ones....

I did some more when we raced the things in Moped Mayhem but we stopped that ten years ago....

I did some diagrams, it was pretty simple stuff you break 2 'tracks' on the circuit board on the opposite side to the connector and solder in a wire to join the two broken bits up.

Trouble is my notes are in the UK in storage and I am here in Australia... I might have a copy on an old hard drive... Maybe.....
Xirious
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Re: Intermittent spark

Post by Xirious »

Hi There,

Not sure if this is the correct place for my post or if I should open a new topic.

While riding, suddenly the engine started sputering. Finally it stopped running.
During initial check I found that I had no spark on either plugs, ground wire connecting battery to chassis was broken and head and rear light bulb blown. All 3 fuses OK. The valve motors don't turn anymore when turning the key.
Supply voltage and ground connection to CDI are ok but funny smell comming from the unit.
My CDI got fried badly (cap, motor driver, diode and possibly some other components).


Could the broken ground wire have been the cause? Besides the broken wire, there is the ground wire from battery to harness which still provides a connection to ground.
Why isn't there a lower rated fuse protecting the CDI?

Anyway, hoping to be able to repair it by replacing the fired components I Was wondering if anybody can tell me where to find the circuit diagram for a 21119-1234 cdi for a KR1-B.
Thought I had seen it on the forum somewhere as an extract from JP document but can't find it anymore.

Thanks in advance,
Erik
Last edited by Xirious on Thu Sep 01, 2022 1:56 pm, edited 4 times in total.
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JanBros
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Re: Intermittent spark

Post by JanBros »

check your voltage regulator output !!
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Xirious
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Re: Intermittent spark

Post by Xirious »

Hi Jan,

Thanks for your VERY quick reply!

I checked the diodes in the regulator and those are fine. When/if I can get the CDI repaired will surely test the regulator is outputing the correct voltage.

Would you have any info on CDI circuit diagrams?

Regards
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JanBros
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Re: Intermittent spark

Post by JanBros »

no, have 2 fried CDI's myself.
never trust only on static measurements, reg's can start to fail when heating up.
first time you start her again, make sure you measure the voltage and watch it carefully when revving. Mine blew up 'cause of faulty reg's.

can't help you with a diagram
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