Yamaha FX HO: Power Loss, Knock Sensor and Intake Pressure

When an FX HO weakens under load, the control unit often has a reason. M-JET DIAGNOSTIC lets you log on a test ride what it sees.

What you record

• Ignition timing and knock sensor messages (code 17)
• Intake pressure (code 29) and intake air temperature (code 23)
• Engine and exhaust manifold water temperature
• Throttle valve angle and battery voltage

Recognizing patterns

If ignition timing drops while intake air temperature rises, the control unit pulls power back to avoid knock. If intake pressure collapses at full load, you look at the intake path and tightness. If everything stays unremarkable, the cause is often mechanical at the pump or impeller. The recording gives you the evidence.

Related topics

• Yamaha FX HO: Reset the Maintenance Warning and Check Hours
• Yamaha FX HO and Cruiser HO (2008–2014) Fault Codes: List
• Yamaha WaveRunner Power Loss: Finding the Cause
• Diagnostics and fault codes for your Yamaha model
• All Yamaha WaveRunner diagnostics 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.