I dropped a coffmans pipe in my 650 and have it pretty well tuned after riding it today for the first time with the pipe. i also have a mariner high comp head to put on but am waiting for a thicker gasket because my compression was way to high with the copper gasket. however i put the copper gasket on with my stock head and the water flow was restricted to a few tiny little holes flowing from the block up to the head. my head used to be almost cool to the touch with the stock gasket and now it will boil water after a few minutes of running. is that way to hot for my ski to be running like that and why is the gasket not cut out to be the full size of those water channels? and do i want those tiny holes with my high comp head?