My 1996 Kawasaki 900 ZXI jet skit lost power and changed sound???

Question

Well this is my first year owning it and i had it out for like the 5th time and when i was out there it quieted down and lost power...i was able to do 58mph now it will only go 45. This is the first year it has seen lots of use in 2 years. It has oil and it doesnt not have any noticeable problems except the ones listed. what could be the problem, Spark plugs???

Answer 1

Sounds like crud as collected on your valve seats.  Ask at your local auto supply store if they've got something that will clean the surface.  If it goes in your gas, it may take a few tank fulls to clear things up.  If thats the problem, you might consider always putting in an additive.

P.S. It may go in your oil. (or both gas and oil).

Answer 2

Check the compression in each cylinder. Sounds like you blew a gasket, or burned a hole in one of your pistons. Assuming you already checked the jet intake for weeds or debris.