these are all really good points i must say... however the bike is in there hands now and im just goin off what they tell me, as you read they said the plugs werent bad but werent new..it passed the leak down test..the air box was clean...and the bike only smokes and burns oil at high rpms...the coolant level is fine no leaks or bubbles when revving..now to answer your exhaust question I dont know...the tip is pitch black as it is burning bad...i dont know when they changed oil but I know they did then the bike sat...I assume they would look through the exhaust as they take down the engine..but whether thats the problem we will see..but I really appretiate the input sounds like you know your engines..o and they did get ahold of yamaha and yamaha i guess was kinda shocked but told them to tear her apart...we shall know and see tomorrow..