Kawasaki 750XI Jetski Power Suggestions

Hi Tech, I own a 1994 Kawasaki 750Xi jet ski and its a great ski; however, I am looking for more power and speed. Ive talked to a local dealer about hop ups, but no dealer was really giving mean answer. 
    Im looking for a bolt-on kit. No major engine modifications (i.e. pistons, cranks, ect.). Some kind of package that will give me a good 4-6 mph increase in top speed and a real punch in acceleration. I was thinking of milling the head, How much psi for pump gas 92 fuel? An exhaust system what kind, brand? An impeller-what pitch? and what other modification must I make to retain proper operation and reliability (i.e. carburetor, ect)
Jake

Jake,
Get a after market performance head 180 lb or have a machine shop mill your head .030 inch's, while retaining a .050-inch squishband clearance. This should bring your compression up to about 180-185 psi. Pump gas octane fuel will be fine. I suggest you change from your stock flame arrestor to an aftermarket air filter so the engine will breath easier. A factory pipe exhaust pipe works well on the Kawasaki 750.  You can use the ski's stock water box. You will have to richin your carbs per factory pipes recommendations. Install a performance impeller.
​Tech