Hi all,

I've been having a problem with bike since few weeks- it was cutting off suddenly occasionally but still ran, until few days since when it just doesn't start

There is no spark to any of the plugs. I checked by putting a screw driver in the leads(as it is a pain to remove the plugs) and position it very close to the engine while cranking and no sign of spark at all...
I used the manual to do some ignition checks:

I measured the voltage on the CDI 6P(to ensure no faulty switch on the loom) connector and resistance of the ignition primary coil and all of this is normal.

I get a resistance of 3.4 ohms at the primary coil terminals and 14kohms at the secondary coil terminals.

I also checked the resistance of the pulse generator and getting a 540ohms between the wires and 0hms between any of the terminals and the ground which according to the manual is fine.

Everything is leading towards a faulty CDI... Any other suggestions will be appreciated.

I read somewhere before that a fault fuel pump relay could "simulate" fault CDI somehow- didn't make any sense to me but dunno - can anyone think of something?

Also someone else mentioned about a diode in the ignition switch fault - any explanation about this as well?

Please recommend something, as I really hope to not have to buy a new expensive CDI?

Thanks,

Jay

 

Engine kill switch?

 

x2 the first place to start is take the kill switch apart, clean it, and apply electrical contact grease into it. Its a bad place for corrosion.

 

This was the very first thing I checked, and the fact that I am getting 12+V on the 6P connector on the CDI is saying that there is no faulty switch on the circuit. Only to be 101% sure I bypassed the switch but same story... I am waiting for another test piece CDI in the following few days so fingers crossed I finally find what the problem is.

Well.. I was hoping it would be a samller (cheaper) problem than the CDI but if it turns out to be this at least I know whats wrong..

Any other suggestions are very welcome and appreciated!

Cheers

 

The kill switch is fine. I did bypassed it just in case anyway..

I am just wandering which one would it be:

Pulse genetrator sensor or CDI...???

Is it supposed to have oil inside the left engine cover (where the pulse sensor is)?

 

yes theres supposed to be oil in that cover I believe.

wha year is your CBR? I'll be partng out my 90 soon.

 

Yes there should be oil in there, when I changed to the +6 Degree Ignition rotor, about a litre came out.

 

Ok thanks for the info guys!

Just to update: the bike is now ALIVE- it was the CDI unit. It did fire as soon as I pressed the start button after replacing the unit.

Thanks for the answers!