Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
It could be particles of crud in the fuel, from a dodgy petrol station, or a dodgy can, or crap in the tank. Try putting a small filter in the fuel line to stop it happening again. Glad you got it running again, try and convince your sister to have ride on it, she doesn't know what she's missing!