2006 Johnson SD 3.5 HP 2 Stroke Outboard Service Manual, PN 5006562, Page 140Get this manual
Running outboard too fast (Overspeeding)
"Too fast" means running faster than outboard normally runs on boatRunning too fast can happen when1) Using flushing device Turn on water before starting outboard Keep 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 DANGER
DO NOT run the engine indoors or without adequate ventilation or permit exhaust fumes to accumulate in confined areasEngine exhaust contains carbon monoxide which, if inhaled, can cause serious brain damage or death