Introduction Jet skiing in South Florida is an exhilarating experience, but nothing ruins a day on the water like an overheated engine. At Broward Motorsports Jupiter, our full-service repair shop specializes in diagnosing and fixing jet ski overheating issues. In this guide, we’ll help you understand why jet skis overheat, common causes, how to diagnose the issue, and most importantly, how to prevent it from happening again.

Why Does Jet Ski Overheating Occur?

Jet skis rely on a cooling system to maintain a safe engine temperature. Unlike cars, which use radiators, jet skis typically use water from the environment to cool their engines. In Florida’s hot climate, issues like overheating are common, especially when debris clogs the cooling system or if the water is particularly shallow or sandy.

Common Causes of Jet Ski Overheating

  1. Clogged Cooling System

    • Jet skis draw water through intake grates to cool the engine. Sand, seaweed, and shells can clog these grates, restricting water flow.

  2. Faulty Impeller or Water Pump

    • The impeller helps push water through the cooling system. Damage or wear can cause inefficient cooling, leading to engine overheating.

  3. Low Coolant Levels (Closed-Loop Systems)

    • Jet skis with closed-loop cooling systems, like some Sea-Doo models, require coolant. Low levels can reduce the system’s ability to cool the engine.

  4. Thermostat Malfunction

    • If the thermostat is stuck closed, it won’t allow coolant to circulate, causing the engine to overheat.

  5. Blocked Exhaust System

    • Saltwater corrosion or debris buildup can block the exhaust, causing heat to build up in the engine.

  6. Electrical Issues

    • Faulty temperature sensors or wiring can cause the overheating warning light to come on unnecessarily, or worse, fail to alert you of a real issue.

  7. Old or Stale Fuel

    • Fuel degrades over time, reducing efficiency and causing the engine to run hotter than usual.

Diagnosing Jet Ski Overheating Problems

Step 1: Check for Warning Indicators

  • Most modern jet skis have dashboard indicators. If you see a temperature warning light, stop immediately to prevent damage.

Step 2: Inspect the Cooling Intake Grates

  • Look under your jet ski for any debris blocking the intake grates.

Step 3: Check Coolant Levels (for Closed-Loop Systems)

  • Locate the coolant reservoir, usually under the seat. Ensure levels are within the recommended range.

Step 4: Inspect the Impeller and Water Pump

  • Remove the pump cover and check for signs of wear or damage.

Step 5: Check for Exhaust Blockages

  • Use a flashlight to inspect the exhaust for corrosion or obstructions.

Step 6: Test the Thermostat

  • Remove the thermostat and place it in hot water to see if it opens. If it stays closed, it needs replacement.

How to Prevent Jet Ski Overheating

  1. Regular Maintenance

  2. Flushing the Engine After Every Use

    • Attach a garden hose to the flush port and run the engine for a few minutes to clear out salt, sand, and debris.

  3. Checking Coolant Levels

    • Always check coolant levels before hitting the water, especially if you have a closed-loop system.

  4. Inspecting the Impeller and Grates

    • Regularly check for debris that could restrict water flow.

  5. Using Fresh, High-Quality Fuel

    • Fill up with high-quality fuel and avoid letting your jet ski sit for long periods with old fuel in the tank.

 How Broward Motorsports Jupiter Can Help

If you’re experiencing jet ski overheating issues, our certified technicians at Broward Motorsports Jupiter are ready to diagnose and fix the problem. Whether it’s a simple flush or a more complex repair, our team has the expertise to get you back on the water quickly.


Overheating can lead to costly repairs if not addressed promptly. Don’t let an overheating engine ruin your day on the water—contact Broward Motorsports Jupiter today to schedule a service appointment and keep your jet ski in peak condition.