I have a 1998 SPX, have had no issues with it yet this season. I put it in the water this weekend and can't get speed. It goes at half throttle but if I have the hammer down it still goes only half. The only thing I can think of is that we used Yamalube in it this weekend. We were out of the normal oil we use so we put in Yamalube. Some friends that also have sea doos said that is what they use and we'd be fine. Could this have done it? Any suggestions on what the problem might be? Thank you!