I have done the same thing several times Converse, going along and then revs a bit and carks it.
Also have left the fuel tap off after I have shut it down to go and empty the catcher.
My Standard 2 had the yellow needle in it - didn't have issues for a good while. Then I built the new shed, and suddenly the trip from shed to lawn went from going over a few bumps, to going smoothly straight onto it.
Took 5 goes one time, then the next it just flat out refused - that is why I was mowing in the dark with the PT commando haha. guess the crooked pavers were freeing the needle up