ok so my blaster has low compression and hasnt been rebuilt in a little over a year (thats what the guy who sold it to me said) and im not gonna pay a shop to do it. my question is can i just get a stock piston of the same size, new rings, and new gaskets or does it need to be bored? i have no idea what i am doing when it comes to this. also, what does a rebuild consist of? may i only need new rings?