2003 Johnson ST 55 HP WRL 2 Stroke Commercial Service Manual, PN 5005483, Page 36Get this manual
INSTALLATION AND PREDELIVERY SAFETY INFORMATION
SAFETY INFORMATION
Before working on any part of the outboard, first read the SAFETY section at the end of this manual
PREINSTALLATION CONSIDERATIONS
Maximum Capacity
WARNING
WARNING
The outboard must not exceed the maximum horsepower indicated on the boat's capacity plateSuch overpowering can cause loss of controlContact the boat's manufacturer if the boat lacks capacity plateBoats designed for remote-steered outboards might be overpowered by tillersteered outboard of the maximum rated horsepowerAsk the boat manufacturer if you are unsure about the boat's suitabilityIncorrectly matched boat and engine transom heights can cause boat instability and loss of controlRefer to Transom Brackets and Jack PlatesPrevent lateral movement and possible outboard loss by using the mounting hardware supplied or hardware of sufficient size, strength, and qualityRefer to OUTBOARD MOUNTINGA mounting surface that is damaged or too thin to support the outboard while underway might fail during operation, causing you to lose controlBe sure the boat's transom or mounting bracket is structurally sound and between 12 in(38 mm) and 14 in(57 mm) in thickness