This ecu is much more complex than that of the cat turbo, which is why nobody has been able to crack it yet and actually come up with a solid flash that works, even the yamaha ecu update is not consistent and many guys are having issues with that, there's a reason for that, and you can be certain it's the same reason that the yamaha factory race vipers are using the old nytro electronics and ignition. That being said, I had a head gasket go on mine recently, no sign of running lean, no detonation, just leaking a bit in one spot, sled ran flawless and you'd have never known except it was slowly forcing coolant back into the overflow bottle, right where the gasket leaked it did cause just a little chip on the top edge of that piston, no other damage but they r replacing the piston since the engine was out because of the starter going anyways. But the consensus was that there was no reason for the head gasket to blow, especially only running 5.5-6 pounds of boost. Head studs right from the start would've kept this from ever happening and a slightly thicker gasket, like what they're using in mine now, would only help matters by lowering compression a bit. In your case, if the head gasket blew bad enough and there was a lot of coolant leaking into that cylinder that could very easily be the cause of the piston looking like that
