2004 SR Johnson 2 Stroke 9.9, 15, 25, 30 HP Outboards Service Manual, Page 324Get this manual
SAFETY Running outboard too fast (Overspeeding)
"Too fast" means running faster than outboard normally runs on boatRunning too fast can happen when: 1) Using flushing device Turn on water before starting outboardKeep engine speed below 2000 RPMWith no load, outboard will run too fast very easilyWear eye protectors
2) Running with the wrong test wheel
This may happen if outboard runs too fast
Use the right test wheel
Running outboards: Exhaust fumes