This takes me back to a Flymo GT4 that came into the workshop. It would start fine and run up well but then suddenly disappear in blue smoke. That was a missing clip leading to the pin machining a slot in the bore. Perfect bit of machining too…
Another, at first unexplained, oil lifting occurrence I recall was a welch plug having moved in a Honda G400 cam shaft centre…started up and ran well at first then oil puthering into air filter via breather… sorry for reminiscing digress here.
On topic, I too have mostly re used clips.
Clive.