I have a 660, with an inline fuel bulb/pump. I replaced the broken fuel pipe joint on (top of the gas tank). After replacing it, I immediately started the rhino up, and it fired and started immediately. I did not leave it running, but shut it off right after starting and idling for a moment.. I went out the next day to start it, and it will not start.. . . . . it cranks, it has spark (new spark plug), it appears to be getting fuel. The engine backfires occasionally while trying to start it. I let it sit a day, thinking perhaps it was flooded, tried again today, no luck, will not start. Still has spark. . . . . Any suggestions??