I use Mobil 1 10W30 on my Ferris with a 25 HP. Kawasaki
The 750 STS Kawasaki Jetski uses 2 cycle engine oil. 2 cycle engine oil is specifically made for use in jetskis.
You do not mix gas and oil in a kawasaki kz 400 motorcycle.
10w30
10w40 Motorcycle oil
most use the engine oil for engine and trans
According to the Kawasaki site you should use SE class SAE 10W40, 10W50, 20W40 or 20W50 oil for the engine. You use SAE 10W oil for the front fork.
Use Kawasaki 10W30 motor oil or some good dino oil in it until you get at least 110 hours on it then you can change to synthetic. We prefer the use of 10W30 Mobil 1 synthetic or Royal Purple but ONLY after 110 hours otherwise the engine will nevr break in and the engine will burn oil.
you may add any 10w40 or 20w50 MOTORCYCLE OIL DESIGNED FOR THE WET CLUTCHES ON MOTORCYCLES.Do not use car oil.
I think it is a 2.5 horsepower engine. There are 4 oil formulas for Kawasaki lawnmower engines. I recommend you use the correct blend as stated in your owner's manual.
SAE 10w30 full synthetic.
It is a 2 cycle so use a Synthetic 2 cycle oil any major brand.
Use motorcycle oil 4 stroke semi or full synthetic 10w40 Grade SE, SF, SG or JASO MA or JASO MA2 with the 2001 Kawasaki ZX6R. Never use automotive oils or 2 stroke motorcycle oils as these do not provide enough protection for the wet clutch or engine.