Originally Posted by
billnorman1
Well. You broke a valve which apparently broke another one with the valve head. This is usually caused by metal fatigue, a broken valve spring, coil bind or overrevving. High temperatures can cause valve heads to drop off. Ignition timing and/or lean fuel mix can exacerbate this issue even in a 4 stroke. Your motor should have a limiter on RPM. Mine does I would presume Honda does too.
Obviously you need a piston and cylinder head, maybe a cam. This can bend a connecting rod and even a crankshaft. In a nutshell, I hope you get a new or remanufactured power head.