I recommend you buy a manual here: YAMAHA MANUAL STORE so you know how to take care of your ski. In my 94 waveraider 700cc manual, it recommends the MMV-FLUSH-KT-03. My ski came with hose/kit which connects down on the side of spark plugs. Hard to describe. But, the manual says never to turn on the water before starting the engine. The water could back flow through the muffler into the crank-case causing severe engine damage. So, its important to know what you're doing. You can also look at newer manuals for free here: My Yamaha Prompt - Owners Manual Look at the 98 waveventure 700 manual chapter 4 for the cooling system flush. Its similar to your motor if not the same.