09 zx6r bogging down at high rpms
Here's the story.
Bike gets to roughly 10k rpm and bogs down, stutters and won't go any higher, no matter the situation.
I have just replaced the fuel pump and fuel filter as they were my first thoughts but still no luck.
The bike is completely stock except for a power commander.
I have a suspicion that the butterfly valve in the stock exhaust is not opening but I can physically see throttle adjusting the valve on the outside.
One other thing that also makes me curious is that i bought the bike with an m4 pipe on it but never rode it quick as i was learning the bike still so i never noticed the high rpm issue, then I changed it back to stock for legal reasons. I did notice though that there was no f.i light on the dash which i've read will come up if you remove the stock exhaust and replace with an aftermarket one so that has also made me suspicious.
I'm looking for ideas or guidance on what to do next that could resolve the issue. I was thinking of putting the m4 pipe on and seeing how it goes with that on it, and then maybe disconnecting the power commander.
Any help would be greatly appreciated!