J/Boats J/109 Owner's Manual - page 36
J/109 OWNER GUIDE
36
Coolant system. The filler cap (it looks like a radiator cap) for the freshwater-and-antifreeze cooling system
is located on top of the engine manifold. Check the coolant level of the manifold and the coolant subtank aft
of the engine, on the port side of the compartment (check when the engine is cool). When adding coolant,
follow the engine manufacturer’s recommendations for the proper fresh water/antifreeze ratio. In climates
where freezing may occur in winter, test the coolant mixture for freezing point. Add coolant as needed if the
system is not drained for winter storage.
Raw-water system. Located furthest aft in the engine compartment, the J/109’s raw-water strainer helps
prevent clogging of the raw-water cooling system and overheating of the engine. Check the strainer basket
often to insure that the flow of cooling water is unimpeded. Unscrew the strainer basket lid, remove the
strainer and clean it, and be sure that the basket is seated properly in the bowl before screwing the lid on
hand-tight.
Exhaust System
The J/109 is equipped with a water-injected water-lift exhaust system that dissipates exhaust heat and acts
as the exhaust muffler. Cooling water can accumulate in the bottom of the water-lock muffler; when de-
commissioning your boat for the season, the muffler either should be drained by unscrewing the drain plug
on the bottom of the muffler, or antifreeze should be added so that residual water doesn’t freeze. The water-
lock muffler can be accessed via the starboard-side cockpit locker in the chaseway under the cockpit.
General Hints To Avoid Problems
•
Monitor brightness of cabin lighting and charge batteries as required by running engine. Batteries are
charged by either the AC battery charger or by running the engine.
•
Stop engine with throttle fuel cut-off, then turn ignition key “off”.
•
NEVER turn engine battery switch to OFF position while engine is running.
•
For best efficiency and fuel economy a cruising R.P.M. of 2,600 - 2,800 works well. Vary RPM levels
periodically when cruising under power for a long distance. Be sure to thoroughly read and follow the
manufacturer’s manual for proper break-in procedure for the standard turbo charged Yanmar Diesel
engine. When not underway, battery charging and refrigeration cooling should be handled via shore
power or an auxiliary generator.
•
Do not run engine at full throttle (3600 RPM) for sustained periods, as breakdown may occur. Most
importantly, find an RPM that runs smoothly and follow the Yanmar guide. Avoid "vibrating" RPM
speeds when possible.
•
Keep engine gear shift lever in "REVERSE" position while sailing to prevent possible "free-wheeling" of
prop
•
CAUTION: The J/109 engine is very quiet, and it is possible to forget that it is running. Before shifting
the gear shift lever into REVERSE when sailing, double check that the engine is turned off.
Engine Safety Precautions
Due to high temperatures it is recommended that after running the diesel for more than two hours you
reduce speed to idle and allow excess heat to dissipate for five to ten minutes.
The most common cause of trouble is contaminated or dirty fuel. Your boat is equipped with a Racor fuel
filter located in the engine compartment and a secondary filter on the engine. The wise skipper carries