Reminds me of this one for some reason...
Dumb guy goes and buys himself a shiny new chain saw. His salesman assures him he'll be able to cut N cords of wood a day with it.
He goes home, but try hard as he might, can only cut N-5 cords.
Disappointed, he takes the saw back and the embarrassed salesman takes it in for warranty repair.
Dumb guy picks it up a couple of days later, but again, hard as he tries, can now only cut N-4 cords... better but not right.
He returns it yet again, and the whole process repeats till dumb guy is finally cutting N-1 cord... better, but still a disappointment.
On his final trip to the store, the salesman apologizes profusely, and explains to dumb guy he's never had an issue with this model, and can't understand whats wrong. Puzzled, the salesman picks up the saw, snaps on the ignition and gives it a smart yank... ring ding ding ding ding, ring ding ding ding ding.
Dumb guy, now visibly shaken, sporting bugged out eyes and slack jaw yells over the din to the salesman, "Whats that noise, Whats that noise?"
Erik