1998-2006 Yamaha F20/F25 Outboards Service Manual, Page 69Get this manual
IJtgr 14fl.1
CONTROL SYSTEM
Idle speed adjustment 1Measure: Idle speed Out of specification
Idle speed: 925 50 rmin
Measuring steps: Start the engine and allow it to warm up for few minutes Attach the tachometer to cylinder #1spark plug lead
Tachometer: VU-08036-A90890-06760