rotivator busted

Hi guys
using rotivateor to break up the dug overs, and all was well until it decided that it didnt like what it was doing and packed in.
engine started to rattle and then stopped, fuel ok oil ok, but when cord pulled no engine but a distinct rattle as it turns over. the engine on top of the blades, seems a bit loose, I was wondering if the drive shaft to the blades has snapped or summit like that. before I strip it, any advice would b e a start.

Also the type of rotovator could make a difference.
Grendel

called coopers and it is a direct import from china. so its a no go there, stripped it down and discovered thet the inlet valve must be cheap metal as it is chipped and deformed and it came of the spring. no compression gained. so need new valve.
cheers

gonna try and get a replacement as it aint that old. even if i got a new valve, the outlet valve is prob cheap too and will go as well.