08 cbr600rr won't start
I bought it from a guy from MI about 2months ago an when I bought it he said it ran last yr but he was unable to get it to start.
An what steps have I missed? That i am unaware of i am not a motorcycle mechanic an i hate electrical issues as well
No? Does that effect the spark?
- remove coil
- insert spare plug
- ground case of plug one engine (or with jumper-cable to batt -neg)
- crank engine
Do you see thick white/blue spark jump plug?
Perhaps. Coils are not powered by EFI system. So they can have power but EFI not necessary working. Do real test for spark:
- remove coil
- insert spare plug
- ground case of plug one engine (or with jumper-cable to batt -neg)
- crank engine
Do you see thick white/blue spark jump plug?
- remove coil
- insert spare plug
- ground case of plug one engine (or with jumper-cable to batt -neg)
- crank engine
Do you see thick white/blue spark jump plug?
Pull out fuse/relay box so we can probe wires underneath.
I didn't skip the relays 🤦🏻 I noted that in a earlier reply that i had swapped my relays an inspected my fuses prior to moving to tracing wires up to the ecu looking for a rubbed raw wire with no results but ill pull it back out an await further information
This is where having official Honda manual is handy.

8. measure voltage on engine-stop relay power-input red wire. volts = ???
9. key ON, kill-switch RUN, measure voltage on engine-stop relay activation-coil power blk wire. volts = ???
10. measure voltage on engine-stop relay power-output blk/wht wire. volts = ???
11. measure resistance to chassis-ground of engine-stop relay activation-coil red/blu ground wire. ohms = ???
12. measure voltage on fuel-pump relay's power-input and activation-coil power blk/wht wires, volts x2 = ???
13. kill-switch OFF, measure voltage on fuel-pump relay's power-output brn wire, kill-switch ON, volts = ??? for 3-seconds
14. kill-switch OFF, measure resistance to chassis-ground of fuel-pump relay's activation-coil ground brn/blk wire. kill=switch ON, ohms = ??? for 3-seconds
15. disconnect fuel-pump connector
16. kill-switch OFF, measure voltage on fuel-pump connector's power-output brn wire, kill-switch ON, volts = ??? for 3-seconds
test fuel-pump (tiny insulated aligator-clips will work)
17. by carefully applying ground to pump's terminal where grn wire connects
18. carefully apply +12v to pump's terminal where power-input brn wire connects
Something is not correct at this stage. Once we identify and fix it, bike will run!
8. measure voltage on engine-stop relay power-input red wire. volts = ???
9. key ON, kill-switch RUN, measure voltage on engine-stop relay activation-coil power blk wire. volts = ???
10. measure voltage on engine-stop relay power-output blk/wht wire. volts = ???
11. measure resistance to chassis-ground of engine-stop relay activation-coil red/blu ground wire. ohms = ???
12. measure voltage on fuel-pump relay's power-input and activation-coil power blk/wht wires, volts x2 = ???
13. kill-switch OFF, measure voltage on fuel-pump relay's power-output brn wire, kill-switch ON, volts = ??? for 3-seconds
14. kill-switch OFF, measure resistance to chassis-ground of fuel-pump relay's activation-coil ground brn/blk wire. kill=switch ON, ohms = ??? for 3-seconds
15. disconnect fuel-pump connector
16. kill-switch OFF, measure voltage on fuel-pump connector's power-output brn wire, kill-switch ON, volts = ??? for 3-seconds
test fuel-pump (tiny insulated aligator-clips will work)
17. by carefully applying ground to pump's terminal where grn wire connects
18. carefully apply +12v to pump's terminal where power-input brn wire connects
Something is not correct at this stage. Once we identify and fix it, bike will run!
Last edited by dannoxyz; Apr 20, 2023 at 02:29 PM.
1. remove coil from bike
2. insert plug into coil
3. using small jumper connect battery +12v to one terminal of coil
4. attach small jumper to other terminal of coil
5. with free-end of 2nd jumper, repeatedly tap it to battery -neg
Do you see thick white/blue spark jump plug?
As always, verify upstream components haven't failed you. In this case, ECU's not sending grounding-pulses to coil to trigger them. Can confirm several ways:
connected to coil-terminals will blink when it detects firing-pulses from ECU. Dimming test-light isn't indicator of anything except that battery-voltage drops when cranking. You can verify this by measuring actual voltage of battery.
Oscilloscope
will also show ECU ground-pulses to fire coil. Will look like this on 'scope.
In this case 'scope will show flat-line of battery-voltage at coil-connector. Absence of ECU pulses DOES NOT mean ECU is bad, just that upstream signal to coil isn't getting there. So again requires investigating upstream and figuring out why ECU's not firing perfectly good coils. It is most likely bad wiring or corroded connectors to sensors, safety interloc-switches, even power & ground wires to ECU have been issue. So each of these upstream possibilities needs to be tested and measured to determine if they're good or bad.
Last edited by dannoxyz; Apr 21, 2023 at 11:33 PM.


