I bought a 2007 yz125 about a year ago and it had a 144 kit in it already. Now I think it's time for a top end rebuild. I looked on motosport for a 144 piston kit with all the gaskets and etc. But I can one, I can only find just the piston. Where can I get the piston kit? Not the big bore kit with the head and all that.

Is it an Athena kit or a modified OEM jug? Buying the gaskets separately is not a chore. All you need is a base gasket and head o-rings or gasket. And you don't even need to pull off the head actually, so you could do with just a base gasket. I re-use the PV gasket unless it's really bad.