bogs

[newyork ultra250]

hi guys i have a 2003 xlt1200 i bought over the winter it has 36 hours on it . when i put it in the water it ran with a bog but would clear up every now a them.i pulled the carbs off and had riva rebiuld them they said there was nothing wrong with them 660$ later. put them on and ski ran ok for three hours and started to run like ****. pull plugs and found it is fauleing #3 changed all plugs ran fine for 10min and fauled it again.let ski sit for 2weeks and it started fine and ran fine for alittle bit.need some ideas.

[newyork ultra250]

thank you