2001-2005 Yamaha XLT800 Overheating

2001 2002 2003 2004 2005 Yamaha XLT800 Overheating

Yamaha WaveRunner XLT800 (XLT-800) overheating refers to when the jet-ski’s engine temperature becomes too hot. Serious mechanical damage can occur if the Yamaha XLT800 engine overheats for too long, such as cylinder head damage, head gasket damage or warpage to the cylinders.

It’s important to identify the causes to an overheating issue and correct it before potential damage occurs. Use the following information to identify possible causes. Check for one or more possible malfunctions:

Engine Overheating

  1. Cooling passages in pump restricted. Inspect the screen and passages.
  2. Pump housing or impeller damaged.
  3. Pump housing passage plugs are possibly missing.
  4. Thermostat or pop-off valve possibly restricted.
  5. Sand or debris restricting cooling water passages in engine.
  6. Damaged or loose cooking hoses or clamps.
  7. Collapsed or restricted exhaust pip or hose.

It’s possible other less common reasons could be causing the Yamaha XLT-800 to overheat but these are the most probable causes. It’s highly recommend you refer to the download factory service manual for additional information regarding overheating issues


  1. My 2004 Yamaha XLT800 is running too hot at idle and the overheat warning indicator blinks, what can cause this?

    • It’s probably a clogged cooling water passage. Is water discharge out from the cooing water pilot outlet? You got sufficient engine oil?

  2. The control is activated when the termoswitch (engine) is on, when the Termoswitch (exhaust) is on or when the engine temperature exceeds 130 °C.

    • Maybe you put the head gasket on wrong? Did you check for obstructed cooling lines. Did debris or sand get into the water jackets?

Leave a Reply

Your email address will not be published.