Mercury Optimax 150, Manual

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OUTBOARD INSTALLATION
63
Fastening the Outboard to the Transom
MOUNTING BOLTS
Outboard Transom Mounting Hardware - Supplied with Outboard
Part Number Part Name Description
10-67755-1 Transom bolt 1/2-20 x 4.50 in. long (2.25 in. thread)
11-826711-17 Nylon insert locknut 1/2-20
12-28421 Washer - Inner 0.516 in. ID x 1.50 in. OD
12-54012 Washer - Outer 0.53 in. ID x 0.87 in. OD
Available Transom Mounting Bolts
Part Number Part Name Description
10-67755005 Transom bolt 1/2-20 x 2.50 in. long (1.25 in. thread)
10-67755006 Transom bolt 1/2-20 x 3.50 in. long (1.25 in. thread)
10-814259 Transom bolt 1/2-20 x 4.00 in. long (2.25 in. thread)
10-67755-1 Transom bolt 1/2-20 x 4.50 in. long (2.25 in. thread)
10-67755-003 Transom bolt 1/2-20 x 5.50 in. long (3.25 in. thread)
10-67755-2 Transom bolt 1/2-20 x 6.50 in. long (2.75 in. thread)
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.
18961
a
b
a - Transom yielding under bolt torque b - Transom cracking under bolt torque
When first determining transom strength, use a dial torque wrench. 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.