1 cylinder out of 4 is working!!!

[linasv]

Hey everyone,

I tried replacing tachometer on my Kawasaki GT550 and after multiple attempts of not making it work I gave up and decided to just not have it, however now only 1 out of 4 cylinders is working!!!

As I understand that must be CDI Unit's fault. I can't think of anything else that could be wrong with it because it was working fine before..

Any suggestions on how I can test the CDI Unit or any ideas what could've gone wrong?

Thanks

[RhynoCZ]

Do you have spark on all 4 cylinders? Is there fuel in the combustion chambers? What type of ignition does it have? I can't remember if the GT550 had contactless ignition or the old point type.

[linasv]

[MCN]

I had a 'module' on a 3 cyl. Honda outboard which went rogue.

I was not sure if it was the module or the coils.

It was possible to disconnect the wire from the module to the coils and make the module fire different coils.

By this method I found that the coils were all OK but the module had two dead circuits.

If you can do that on your bike then you may eliminate the good section and find the culprit.

I would not be surprised if three coils have failed though. A Triumph bike I had was forever blowing coils.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[RhynoCZ]

GT/GPz 550 has only 2 coils. Which theoretically means faulty coils can only give you 2 dead cylinders or all of them.
Anyway, spark plugs out and check for spark. Do you park it outside? It's getting damp outside, moisture could also cause this issue.

Also, one thing that happens on old bikes, cracked spark plug caps. I had this when I got my GPz, if the bike got wet, it wouldn't start. Once it was dry, it ran alright.
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[bypass2]

Just a guess try the working plug in another cylinder see if it works. or see if the other 3 plugs spark

[Tankie]

1 coil does 1 and 4, the other does 2 and 3, so check your leads are on correctly.
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Always learning, everyday is a school day

[Nobby the Bastard]

Most (but not all) paired coils have a single coil going through both plugs as one circuit (rather than twin circuits and two coils in parrallel.

In which case it's almost impossible to lose only one spark as, if one side doesn't spark, the other side can't either because it's only one circuit.

it's possible to check the coils by seeing if you can reach earth on the metal mounting points through the leads.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050