Disassembly And Reassembly; Disassembly - Yanmar 3JH4E Service Manual

4. Disassembly and reassembly

4.3 Disassembly and reassembly

4.3.1 Disassembly

• Preparation on a boat
For engines mounted in an engine room of a ship, remove the piping and wiring connecting them to the
ship.
1) Remove the electric wiring connecting the electronic control system and the engine.
2) Unplug the extension cord for the instrument panel from the engine.
3) Remove the wiring between the starting motor and the battery.
4) Remove the exhaust rubber hose from the mixing elbow.
5) Remove the rubber hose connecting the coolant recovery tank to the filler cap.
6) Remove the seawater inlet hose for the seawater pump (after making sure the seacock is closed).
7) Remove the fuel oil inlet rubber hose from the fuel feed pump.
8) Remove the body fit (reamer) bolts and disassemble the propeller shaft coupling and thrust shaft
coupling.
9) If a driven coupling is mounted to the front drive coupling, disassemble.
10)Remove the flexible mount nut, lift the engine, and remove it from the engine base.
(Leave the flexible mount attached to the engine base.)
• Disassembling an engine in a workshop
(1) Drain seawater
1) Open the seawater drain cock(s) to drain the seawater.
Note:
Don't forget to open a drain cock on a clutch cooler for 4JH4E,4JH4-TE and 4JH4-HTE.
2) Open the cocks for fresh water and extract the fresh water.
Note:
One drain cock is behind the belt cover only for 3JH4E and 4JH4E.
Remove the belt cover and open the cock.
Model
3JH4E
4JH4E
4JH4-TE
4JH4-HTE
Note1:
The marine gear boxes with a drain cock of clutch cooler are as follows;
4JH4E: ZF30M, KM4A1
4JH4-TE and 4JH4-HTE: ZF30M, KM4A2, KMH4A
Drain cocks
in fresh water line
3 cocks 2 places (1 cock and a side cover of seawater pump)
2 cocks 2 places (a side cover of seawater pump and 1 cock on
clutch cooler)
3 cocks
Note1
3 places (a side cover of seawater pump and 2 cocks on
3 cocks clutch cooler and intercooler)
Note 1
Drain cocks in seawater line
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