I have a 2015 Spark HO 90 2Up. Never had any issues. First time out this season it had about a 1/4 tank of fuel from last season and I filled up with the highest octane fuel available at the pump. Took off for first run and would run past 28 mph and overall felt rough. Pushed around the lake for about 20 min hoping it would pass through any old fuel issues with no luck. RPMs I believe would get into the 5k area. Ran fine on last run of last year and was winterized by a Seadoo dealer. Any thoughts?