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I wanted to cover a few point

3/10 owners will at some point experience ignition failure (even due to attempted theft)

If someone has attempted to hotwire your bike this post
will be your best friend.

1. If your bike is getting no power ; you may want to check the main fuse located under the airbox a bit. There will be a spare. It may have blown!

2 If your bike gets power but does not fully prime the fuel pump (you may or may not hear the difference). It will crank without starting. This will be a fault of the zener diode . THE diode wire from the ignition is orange on the cbr300 and pink on the cbr250r.


So how that diode works on the cbr is the diode puts out exactly 9v in the initial start up , the ECM receives the 9v in a sort of handshake. After the ECM receives the "handshake" the fuel pump will be triggered. After the bike starts the diode will no longer be required, the handshake will be valid for 30 seconds after the bike is still shut off.

When the diode blows in the ignition from hotwiring it is caused by the 12v constant power to the ignition being supplied reverse into the diode when it is meant to supply the 9v conversion to the ecm.

This will also cause the main fuse behind the air filter to blow.

When the diode has failed it can be emulated with a regular 9v battery from the positive (+) battery terminal on the 9v to the orange wire (cbr300) or the pink wire (cbr250) and the negative(-) terminal on the 9v to the negative 12v battery terminal.

This will mimic the diode. Causing the Fuel pump to engage.

Please correct me if I am wrong but i have tested this.

Also you can mimic the diode with the 9v battery and then use a toggle for the two other wires to the ignition. These ignitions are a hassle to replace because of the headless bolts I believe.

I am a victim of bike theft. Take this post as a precaution . Or a solution
 

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HELP!!! I'm facing the same issue again. It happend once a few years ago. The zener diode broke.after replacing it it worked just fine. And then a few weeks ago it broke again.and I put in a new one. But this time the pump does not prime. I'm stuck here.is it a wiring fault,relay fault. I changes out the relays too on the frame to the left.the pump is brand new.primes if I give it direct power.
 
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