HAMILTON WATER JETS. Nature. Newton’s Third Law of Motion “Every action has an equal and opposite reaction”. . Water jet - Main parts. Cast aluminium pump u nit and intake transition duct Stainless steel impeller Astern deflector Steering nozzles. Water Jet Advantages .
Position of the bucket for:
Ahead Neutral Astern
Cavitation causes a loss of performance and results in serious damage to the waterjet components.
Cavitation can be caused by…
• Hump Conditions • Overload • Weight too far aft • Bad weather or sea conditions • Blocked intake screen • Blunt or damaged impellers • Excessive impeller tip clearance • Poor installation
Cavitation can be prevented by…
1 Increasing the jet intake pressure – i.e.: Increase boat speed but do not increase power
2 Reduce rpm – less throttle – coarser impeller, i.e.. less rpm (steeper pitched blades)
3 Reduce flow plus fit a smaller nozzle
Avoid pumping stones, sand and debris through the Jet Unit as this will blunt and wear the Impeller. The following diagrams illustrate good and bad practice…