Im just a kid just mucking around in my garage with a motorised bike. The other day I windowed out my piston (a lot) and now the engine won't start. I have a HP carburettor and a very slightly sanded cylinder head. I see people talking about reed valves when they mention windowed pistons. What's the relationship between these? I know I have a spark, my fuel line is fine ect. I know the problem is either with my jet or the piston. Any help as to what I should to?