I'm with Trevor on xo3 series. I have a 403...
. It has a tendancy to leak at the "impeller housing". Lubricate the o-ring prior to assembling the housings and press together slowly and gently. I won't run mine without a small Rubbermaid container around it. "once bitten..."
Priming is a term used to remove the air from the system and replacing it with water. Just wrap your lips around the outlet hose and start suckin' on that bad boy until you get a mouthful of that salty stuff...
(Don't anybody even bother replying to that last statement 'cause I know whet you're thinkin'...)