Motorcycle Diagnosis


adulbrich

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May 11, 2014
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Ames, Iowa
Hello, sorry for the long read, but I want people to know what I have tried so far.

I have a 2007 Honda CBR1000. A month ago, it died while I was riding it. Gauge cluster was still on and the red indicator light came on, but the engine cut out. Cranked, but would not start. When cycling the key, the fuel pump would not cycle as usual.

First thought was pump went out. I got my bike back to the auto shop I work at, and put power directly to the fuel pump with a power probe. The pump worked. Tried cranking the engine while manually putting power to the pump, in case a wire was bad. Still nothing.

Next step was checking injector signal with a Noid light kit. Injectors weren't getting signal when cranking the engine over. At this point, I suspected the ECU. That's an easy enough fix, so I ordered a used one off ebay. A few days later, I got the replacement ECU. First I tried starting my bike before swapping ECU's and it wouldn't go. Plugged the replacement in and the bike started right up. I don't know why, but out of curiosity, I swapped the original ECU back in, and the bike also started fine. I've rode it for a few weeks now without issue, but it died again today while moving. Once I got it back home, I swapped the ebay ECU back in, and it still wouldn't start. Haven't re-tested injector signal yet with a light, but the fuel pump does not cycle with either ECU.

Unless I'm wrong, there's no way to "scan" 07's for codes if it's a sensor or something. I have heard of some bikes using an indicator light to flash in blips to tell you the code it is setting. That would be nice. I have two complete engines for CBR1000's in my garage right now. One is an 04, and the other is an 06. The 06 should be about the same, so I'm about ready to start swapping sensors over and "throwing parts at it" until the problem is solved. If I knew it was a specific sensor, I would just buy a new one.

Any advice for further diagnosis?
 

Popwarhomie

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I don't know much about motor scooters but does it still have the Bank Angle Sensor or have you bypassed it?


The sensor shuts off fuel/spark when tripping thinking the bike is on its side.
 
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adulbrich

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May 11, 2014
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Ames, Iowa
  • Thread Starter Thread Starter
  • #6
Thanks for the tips guys, but @Bosston on 1000rr.net was right! It was the switch on the right handlebar. I checked the wiring diagram, and the kill switch is a "dead man switch" that cuts power to the fuel pump and injectors. After flipping the switch back and forth several times, I was able to get my bike to start. Flipping the switch while the bike is running kills the engine, but the gauge cluster stays on and the red indicator light comes on. When the switch is in the off position, the fuel pump will not prime when cycling the key.

I ordered a new OEM Honda switch for only $42 shipped. Temporarily, I took my switch casing apart and directly soldered the wires connected to the switch. I've rode my bike around all day, starting it 7 times today without problems.

Once again, thanks for the help!
 

metalheadjoe

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Oct 21, 2007
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Thanks for the tips guys, but @Bosston on 1000rr.net was right! It was the switch on the right handlebar. I checked the wiring diagram, and the kill switch is a "dead man switch" that cuts power to the fuel pump and injectors. After flipping the switch back and forth several times, I was able to get my bike to start. Flipping the switch while the bike is running kills the engine, but the gauge cluster stays on and the red indicator light comes on. When the switch is in the off position, the fuel pump will not prime when cycling the key.

I ordered a new OEM Honda switch for only $42 shipped. Temporarily, I took my switch casing apart and directly soldered the wires connected to the switch. I've rode my bike around all day, starting it 7 times today without problems.

Once again, thanks for the help!
You got me interested, since my last bike was a carbureted 2001 R6. Your bike has an electric fuel pump? Does it have a return line? I thought bikes were usually gravity-fed, with Buells being an exception.
 
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adulbrich

Lock up your daughters!
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May 11, 2014
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2
Ames, Iowa
  • Thread Starter Thread Starter
  • #9
You got me interested, since my last bike was a carbureted 2001 R6. Your bike has an electric fuel pump? Does it have a return line? I thought bikes were usually gravity-fed, with Buells being an exception.
Yeah, it does have an electric fuel pump. It's electronically injected, and has electronic ignition timing. It actually doesn't have a return line. I assume there is a pressure relief system near the output of the pump that is still inside the tank, to prevent over-pressure.

One thing that's odd about my bike is that it's a 4 cylinder with 8 fuel injectors. One primary and one secondary for each cylinder. I didn't even realize it until I tore into it this last time.
 

Slo_Ride

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You got me interested, since my last bike was a carbureted 2001 R6. Your bike has an electric fuel pump? Does it have a return line? I thought bikes were usually gravity-fed, with Buells being an exception.
Yamaha was still using carbs in 01? Suzuki went to fuel injection on '00.
 

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