Gone Outdoors

How to Troubleshoot a Jet Ski That Runs Hot

by Andrea Walk

Personal watercraft, or jet skis, require preventive maintenance on a regular basis. Even then, sometimes problems can arise. One such problem is overheating. Jet skis use an impeller system, along with cooling lines, to circulate water through the engine to keep it cool. If the jet ski is overheating, one of these two parts is usually the problem. Troubleshooting and correcting a jet ski overheating problem may take one to two hours.

1. Access and inspect the hoses running to the cylinder head. Accessing these hoses, which are near the engine, involves removing the engine compartment cover. Open the cover by either unclasping the latches or removing the bolts that hold the cover in place with a wrench. Inspect the lines for cracks, holes or leaks. If the lines are damaged, remove them with a screwdriver and then replace them with new ones.

2. Access the water pump by using a screwdriver to remove the ride plate. Use the wrench to remove the bolts on the water pump and lift the siphon bilge pump out to expose the impeller. If the impeller is nicked or extremely corroded and dirty, remove the bolt holding it in place and remove the impeller. Apply marine grease to the new impeller and set it in place. Tighten the impeller nut, replace the bilge siphon pump and replace the water pump bolts. Also reinstall the lift plate with the screwdriver.

3. Access the cooling line under the seat and remove the line. Connect a water hose to the cooling line and turn on the hose and jet ski. Look to see if water is being ejected from the back of the jet ski. If not, there may be a blockage. Turn off the water hose and the jet ski and use an air compressor with a hand-held blower attachment to try to blow out the blockage.

Items you will need
  • Wrench
  • Screwdriver
  • Replacement hoses (if needed)
  • New impeller (if needed)
  • Water hose
  • Air compressor with hand-blower attachment

References

About the Author

Andrea Walk began writing in 2001, authoring user guides for technical software. She holds a Bachelor of Arts in political science from Loyola University, where she was a member of the Dean's Grade Review Committee for English. Walk is a member of the Automotive X-Prize team Global-E.