When I'm stalled in a story, it takes a major scene change to get me involved again. In my head, the conversation between me and the story sounds like a rejected lover trying to woo back the girl. (Or, if you've been watching too many commercials lately, a dingy mop trying to woo back the blissfully happy Swiffer-having housewife.)
Story: "Oh, please come back. I need you!"
Me: "But I'm so bored with you."
Story: "But I have all these wonderful qualities! Look at my plot! Is my plot not enough for you?"
Me: "Eh, it's not that."
Story: "I've got a fist fight coming up in a few chapters."
Me: "Too little too late, sorry."
Story: "What about sticking the protagonist in a bar with his sociopath ex-bully and getting them both drunk and confessional?"
Me: "Baby, I knew there was a reason I was with you!"
And then there's a touching making up scene wherein I giggle madly over the keyboard, my characters get sloppy drunk, and I'm in love with the story all over again. Maybe I should write my characters getting drunk every time I get stalled on a chapter. That'd make for some interesting scenes (most of them to be revised out of the manuscript later). It probably wouldn't work as well for YA fantasy.
At any rate, I'm back into novel #3, and my narrator is about to start getting weepy about his existence over a girly drink. Possibly with a tiny umbrella in it. Story: redeemed.