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Discussion Starter #1
Ok here goes;

So I have the C65 code showing, but I’m convinced it has nothing to do with the clutch. But I’m also not convinced it has anything to do with the ISC (Idle Speed Control) valve which is what the Haynes manual says.

I did have aftermarket, (Puig) levers for about a year before the code first appeared but I’d heard about the clutch switch fault so I replaced the levers back to standard and I replaced the clutch switch and perch. I have also checked the wiring from the switch to the ECU and there is no ground fault/good continuity. The switch also does what it should, i.e. ground the low voltage wire when the clutch is pulled in. So I’m pretty sure it’s not the clutch.

I replaced the ISC valve but that also made no difference; every time I turn the ignition on, the FI light has reset and the bike runs and idles fine. I ride for an undetermined amount of time and at some point, when I shut/blip the throttle to change down, the FI light comes on and the normal GSXR smooth fueling has disappeared. The slightest throttle movement reacts like an on/off switch, lurching on opening and chopping the fuel on closing. It doesn’t stall the engine and it is ‘manageable’ with an extremely delicate wrist, and it behaves like that until I turn off and on the ignition, whereby it runs normal again, for a while...

So I’m convinced it has something to do with the ISC system, just not sure where to go from here. Any help or suggestions would be greatly appreciated, cheers!

Point to note; before I replaced the ISC valve I checked for resistance which according to specs was low. I however checked the new valve and the readings were the same. So either the new valve might also be no good, (unlikely) or there was never anything wrong with the old one and my meter is less than accurate, (more likely). The wiring to the ISC valve checks out ok.
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