Powerhead Reassembly And Installation; General - Mercury 225 EFI Service Manual

POWERHEAD
d. Plug tester into electrical outlet.
e. Observe temperature at which thermostat begins to open. (Thermostat will drop off
f.
g. Unplug thermostat tester.
h. Replace thermostat if it fails to open at the specified temperature, or if it does not fully
NOTE : BE SURE that water in thermostat tester is allowed to cool sufficiently [below 110 F
(43 C)] before testing the other thermostat.

Powerhead Reassembly and Installation

General

Before proceeding with powerhead reassembly, be sure that all parts to be re-used have
been carefully cleaned and thoroughly inspected, as outlined in "Cleaning and Inspection,"
preceding. Parts, which have not been properly cleaned (or which are questionable), can
severely damage an otherwise perfectly good powerhead within the first few minutes of op-
eration. All new powerhead gaskets MUST BE installed during reassembly.
During reassembly, lubricate parts with 2-Cycle Outboard Oil whenever "light oil" is speci-
fied. Mercury/Quicksilver part numbers of lubricants, sealers and locking compounds are
listed in "Mercury/Quicksilver Lubricants and Sealants" located in section 1A, and special
tools are listed in "Powerhead General Information," preceding.
A torque wrench is essential for correct reassembly of powerhead. DO NOT attempt to
reassemble powerhead without using a torque wrench. Attaching bolts for covers, housings
and cylinder heads MUST BE torqued by tightening bolts in 3 progressive steps (following
specified torque sequence) until specified torque is reached (see "Example," following).
EXAMPLE: If cylinder head attaching bolts require a torque of 30 Ib. ft. (41 N·m), a) tighten
all bolts to 10 Ib. ft. (13.5 Nm), following specified torque sequence, b) tighten all bolts to
20 Ib. ft. (27 Nm), following torque sequence, then finally c) tighten all bolts to 30 Ib. ft. (41
Nm), following torque sequence.
Page 4A-56
thread, that was installed in Step "a", when it starts to open.) Thermostat must begin
to open when temperature reaches 118 -122 F (48 -50 C).
Continue to heat water until thermostat is completely open.
open.
51087
90-884294 OCTOBER 2001