No spark - modern spark unit replacement equivalent?

[Nipedley]

Hi guys,

On my CBR 600F (1988 model), I've gone through various periods of no spark, to a very weak spark, and now back to no spark, while I've been doing it up (it's not been running during this time). The things that have changed while the spark has gone from weak to none have been things like tyres etc, nothing electrical

I've tested the pulser coils, charged the battery (good battery), checked the coil resistances, and am getting no spark from either coils, at this point I'm thinking it has to be the spark unit?

Is there any kind of modern replacement for a spark unit? I'm just thinking if I have to use an at this point 25 year old replacement spark unit then it's just another failure point waiting to happen

Sadly the Haynes manual doesn't give any information on being able to test the spark unit, I tested both terminals of the ignition coils (1 live with ignition and 1 from the spark unit) and both were giving a solid 12v, not sure how coils work electrically (Does the wire from the spark unit pull it to 0v to spark?)

Thanks for the help

[BTTD]

This book is pretty bloody good, if I could be bothered to get it out and read it, I could answer your question. Someone else will chip in...

https://www.amazon.co.uk/Motorcycle-Electrical-Systems-Troubleshooting-Motorbooks/dp/0760327165/ref=sr_1_5?s=books&ie=UTF8&qid=1385841593&sr=1-5&keywords=motorbike+electric

[temeluchus]

Check the ignition switch works (there should be power to the coils when on, none when off).

You can check the coils spark by connecting the coil directly to positive, then to negative. when you disconnect the coil from the battery it should spark.

Check the wiring diagram and try and power the ignitor directly from the battery and bypass the loom, to see if the engine will still run.
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Some shite cruiser. Now with guns and FREEDOM!

[Kickstart]

Hi

Ignition units are generally pretty reliable.

The coil works by having 2 coils of wire inside it. One is the low tension side and receives 12v through it (there should be continuity over the 2 LT connections). This generates a charge in the high tension coils within the coil unit. The ignition unit interrupts the 12V supply to the LT side, at which point the charge in the HT side collapses, discharging through the HT lead to and the spark plug.

All the best

Keith
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