CBR Forum - Enthusiast forums for Honda CBR Owners - 1999 CBR600F4

- CBR 600F4 (https://cbrforum.com/forum/cbr-600f4-18/)

- - 1999 CBR600F4 - no spark at any of the 4 plugs (https://cbrforum.com/forum/cbr-600f4-18/1999-cbr600f4-no-spark-any-4-plugs-104187/)

Quote:

Originally Posted by dannoxyz (Post 1352827)

Well, wire can be broken internally and not show any faults on outside. We'll have you test and measure every wire with multimeter later.

1. how have you verified no-spark?

2. is there petrol flow to carbs? as in measured fuel-pump flow for 10-sec? How much did you collect?

3. disconnect ignition-module, key ON, measure voltage at black wire terminal at connector. Volts=???

4. measure resistance to chassis-ground of grn wire at connector. ohms = ???

5. measure resistance to chassis-ground of lite-grn wire at connector. ohms = ??

Unfortunately the motor now sits on a dolly since i swapped a completely different make and model motor into the F4 frame. I tested spark at the head and frame when the motor was still in the bike. I used a multimeter to test all the wires for breaks. I even undid the factory tape on the harness to verify there were no burns or shorted wires.

I'm not a mechanic but I can usually sort this kind of crap out. I ended up installing a fuel injected 2005 gsxr 750 motor I had running on a stand. I just want to get this figured before I die or it gets tossed in the trash. 🤣

Quote:

Originally Posted by David43Abq (Post 869236)

FINALLY !!!!!!!!!!!!!! It's ALIVE !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
anyone who ever has a no spark issue on a Honda motorcycle, please read !!!!!!!
There is a diode in the switch base of the ignition switch. IF that diode pops for any reason you will have a no spark/no fuel pump issue. The value of the diode is 3.9v 0.5watt part number NTE5007A. My 99 will be back on the road soon !!!!!!!! yay ... btw, it's a friggin .39 cent part ...

I cut my ignition wires cuz lost key so im having same issues do i need that diode to get spark regardless??

Quote:

Originally Posted by Ryan1985 (Post 1353221)

I cut my ignition wires cuz lost key so im having same issues do i need that diode to get spark regardless??

How do you put fuel in it with no key? Just get a replacement ignition switch/key off ebay.

Quote:

Originally Posted by David43Abq (Post 869236)

Took on a cbr900rr that had the same problem, previous mechanic was just throwing new parts at it and gave up saying it needed a full new loom. I looked at the full schematic for the wiring diagram and tested everything and couldn't find a problem anywhere. I seen the resistor under the ignition but took no notice of it until I read this post. Resistance across it was all over the place and the pink wire was at 12v until I touched the resistor itself and the voltage kept changing, the resistor is broken but got it to hold 9v Temperley and all of a sudden I have spark again. Something so small would cause someone to sell/scrap a bike. A big thank you to you 👏👏

Thanks for the update and welcome to the forum.
That resistor is the cause of many problems with these bikes, esp when installing aftermarket ignitions onto them.

It's not a resister - it never was a resister - it's a DIODE. Its job is to reduce the battery voltage to 9v to trigger the ECU to understand the ignition switch has not been bypassed. It's an anti-theft measure.

Sorry, my bad, yes a zener diode!

Quote:

Originally Posted by Al1040 (Post 1361395)

Sorry, my bad, yes a zener diode!

Can it cause the bike to misfire at high revs under load? That's the problem I'm having now

if vibration is causing it to fail then I expect so - it will cause the ECU to crap out.

Quote:

Originally Posted by rockpool (Post 1361550)

if vibration is causing it to fail then I expect so - it will cause the ECU to crap out.

I have a new diode soldered in, 9 volts at the ecu but ignition cuts and misfires at high revs under load