YANMAR

Chapter Three
Operation, Lubrication, Maintenance
and Tune-up
A diesel engine must have clean air, fuel, and oil. Regular
preventive maintenance and proper lubrication will
pay dividends in longer engine and transmission life, as
well as safer boat operation.
The lubrication and maintenance intervals provided in
Table 1 are those recommended for normal operation. If
the boat is used under continuous heavy duty or other severe
operating conditions, including infrequent use, perform
maintenance and lubrication more frequently.
Keep the engine and accessory units clean and free of
dirt, grime and grease buildup. It is much easier and safer
to perform service on a clean engine. It is also much easier
to pinpoint any leaks.
Tables 1-6 are located at the end of this chapter.
NOTE
Except where specified, F and D series engines
are included when a basic model number
is specified. For example, ifmodel 3GM
is called out in a procedure, the procedure
also applies to 3GMD and 3GMF
FUEL REQUIREMENTS
The recommended fuel is number 2 (2-D) diesel fuel.
Be sure the fuel is clean and free of water.
NOTE
Poor fuel is one of the leading causes of
rough engine operation orfailure to start.
Dirty fuel or water in the fuel can cause expensive damage
to the fuel injection pump and fuel injectors. Refer to
Chapter Seven.
PREOPERATIONAL CHECKS
Before starting the engine for the first time each day,
perform the following checks:
1. Remove the engine compartment cover or hatch and
check for the presence of fuel fumes. If the boat is
equipped with a bilge blower, turn it on for a few minutes.
If the smell of strong fumes is present, determine the
source and correct the problem before proceeding.
WARNING
Always have a Coast Guard-approved fire
extinguisher close when working around the
engine.
2. Check the engine oil level as described in this chapter.
Add oil if the level is low.
3. Check the electrolyte level in each battery cell as described
in this chapter. Add distilled water if necessary.