[RCW]

I would take a can of spray oil, WD-40 works fine, and start the engine and while it is idling spray around the two sides of the intake manifold where it joins both cylinder heads, and where the carburetor joins the manifold with that elbow and two gaskets. If the idle speed changes while spraying the oil, then you have a vacuum leak and will need to resolve that first.

Usually when the high idle that cannot be turned down with the throttle stop screw occurs it is a combination of a vacuum leak and too high a float level, or a vacuum leak and the carburetor float valve is leaking from a bad Viton (synthetic rubber) tip on the needle and not shutting off where it should - a slight shadow on the tip is too much wear.

The other common problem is misadjusted governor linkage. If that linkage is set too tight or missing one of the springs it will run at a high idle that will cause all sort of diagnostic nightmares.

The governor is listed on Kawasaki.com in the parts section as the "control." Take a look at the diagram and make sure everything is present on yours. Also be sure to check the primary speed stop screw on that linkage to make sure it is properly adjusted.

If you want to avoid future water pump failures put a small jar of Barrs Leak in the coolant in the engine, not in the overflow tank. That neutralizes and coats the metal surfaces and prevents rust, and it lubricates the water pump seal. I have never had to replace a water pump once Barrs Leak was used. Use the genuine Barrs Leak that has the oily fluid and the stuff that looks like rat droppings, anything else is a waste of time and will not work. Do not waste your time on the Barrs Leak tablets, they are also useless, you want that oily fluid from the bottled type in the cooling system.