Mercury 40 JET FOURSTROKE Operation, Maintenance & Installation Manual page 92

CHECKING BOAT TRANSOM CONSTRUCTION
IMPORTANT: Determine the strength of the boat transom. The outboard
mounting locknuts and bolts should be able to hold 75 Nm (55 lb‑ft) of torque
without the boat transom yielding or cracking. If the boat transom yields or
cracks under this torque, the construction of the transom may not be adequate.
The boat transom must be strengthened or the load carrying area increased.
a - Transom yielding under bolt torque
b - Transom cracking under bolt torque
Use a dial torque wrench to determine transom strength. If the bolt or nut
continues to turn without the torque reading on the dial increasing, it is an
indication that the transom is yielding. The load area can be increased by using
a larger washer or a transom reinforcement plate.
a
a - Large transom washer
b - Transom reinforcement plate
OUTBOARD INSTALLATION
a
b
82
18961
b
33962
eng