GSX-R Sputtering - codes C24,25,26 & 27.

I am trying to resolve an issue on a 2007 GSX-R 750.

It runs fine until around 5,500-6,000RPM, then the warning light starts flashing and when I read the dealer codes by shorting the little white box underneath the seat I get: C24, C25, C26 and C27. These are ignition signals for all the cylinders.

Motor starts and idles fine. When it goes over the afore mentioned RPM, it sputters like crazy at ~ 6,000RPM and won't go over 10,000RPM. This is with or without load.

I have just changed the spark plugs, old ones were in poor condition - no difference.

Don't see any kinks in the fuel lines. There's no PC or similar installed.

Could a crank position sensor do that even the code doesn't come up for it?
Would a quick shifter affect anything (prime suspect at this moment)?

Please advise if you have encountered this problem.

Do you have a quickshifter installed by chance ? I'm seeing lots of threads online mention the QS being the cause of the codes due to the interruption timing they require (if set improperly).

Someone also mentions checking the crank position sensor.

Online the codes seem to reference:

Just some threads/info to read over in case it applies to you, or might rule some things out:

http://www.gixxer.com/forums/137-08-10-gsx-r600-750/200490-bazzaz-c24-c25-c26-c27.html

http://www.gixxer.com/forums/236-05-06-gsx-r1000/367330-need-help-c24-c26-c27-codes.html

https://www.youtube.com/watch?v=PCJfbGf1bik

Thank you for the response. I have already isolated the issue.
It was the quickshifter. Instead of setting it up I uninstalled it.
Don't really need one.

Glad to hear you got it sorted. They are a definite "nice to have" type of item, more so if you're into racing than just touring around the streets. I never realized how finicky they could be until I searched your problem.

DemonPig said:

Thank you for the response. I have already isolated the issue.
It was the quickshifter. Instead of setting it up I uninstalled it.
Don't really need one.

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