M-JET DIAGNOSTIC · YAMAHA

Yamaha WaveRunner Rough Idle: Diagnostics

The engine idles higher, then lower, or stalls when docking. M-JET DIAGNOSTIC shows you which sensors stand out and, on many models, offers idle learning.

Possible causes

  • Dirty throttle valve or bypass stepper motor
  • False air in the intake area
  • A sensor with an implausible value, for example intake pressure or temperature
  • Weak battery or poor ground
  • Ignition coil or injector with misfires

Procedure

Read the fault memory and watch engine speed, throttle valve angle, intake pressure and voltage at idle. Then test ignition coils and injectors individually if one cylinder is suspect. If the throttle valve was cleaned or replaced, start the idle and throttle valve learning afterwards. The craft may only run with a water supply, otherwise the engine overheats.

Related topics

Everything runs via app over Bluetooth, for Yamaha WaveRunners from model year 2002 to today. Learn more about the M-JET DIAGNOSTIC for Yamaha WaveRunner.

You also ride a Sea-Doo or Can-Am? The M-JET DIAGNOSTIC is available for BRP vehicles too.

To the M-JET DIAGNOSTIC for BRP ›