Yanmar 4JH3-TE, Operation Manual

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44 5. MAINTENANCE & INSPECTION
(7) Checking the Tension of the V-Belt of the Alternator
When there is not enough tension in the V-belt, the belt
will slip making it impossible for the alternator to gener-
ate power.
Additionally, the fresh water pump will not work causing
the engine to overheat.
Check the tension of the V-belt in the following manner.
1. Press the V-belt down with your thumb at the middle
of the belt to check the tension.
The give in the V-belt should measure about 8 10mm
at the depression.
2. To adjust the V-belt tension, loosen the set bolt and
move the alternator.
3. Replace the belt if it is damaged.
Parts No: 25132-004600(A-46)
NOTICE:
• If the V-belt tension is too tight, the belt and the bearings of the alternator will be dam-
aged.
• Be careful not to spill any oil on the V-belt as this will lead to stretching and slippage.
5.2.4 Inspection Every 500 Hrs.or 2 yrs.
(1) Adjustment of Intake/Exhaust Valve clearance
This maintenance requires specialized knowledge. Consult your Yanmar dealer or distributor. Adjustment is
necessary to maintain the correct timing for the opening and closing of valves. Neglecting adjustment will
cause the engine to run noisily and result in reduced power output and other damage.
(2) Inspecting and Adjusting Fuel Injection Valves
This maintenance requires specialized knowledge. Consult your Yanmar dealer or distributor. Fuel injection
must be adjusted to ensure optimal engine performance.
Fresh water
pump
V-belt
Set Bolt
Alternator
Press down with thum