TROUBLESHOOTING104 JH Series Operation ManualIs there water, oil or fuel leakage? Arethere any loose bolts or connections?Check the engine room daily for any leaksor loose connections.Is there sufficient fuel in the fuel tank?Refill fuel in advance to avoid running outof fuel. If the tank runs out of fuel, bleedthe fuel system. See Bleeding the FuelSystem on page 40.When operating the engine at low speedfor long periods of time, race the engineonce every 2 hours. Racing the enginewith the clutch in NEUTRAL, acceleratefrom the low-speed position to thehigh-speed position and repeat thisprocess about five times. This is done toclean out carbon from the cylinders andthe fuel injection valves.NOTICENeglecting to race the engine will result inpoor smoke color and reduce engineperformance.Periodically operate the engine nearmaximum speed while underway. This willgenerate higher exhaust temperatures,which will help clean out hard carbondeposits, maintain engine performanceand prolong the life of the engine.TROUBLESHOOTINGINFORMATIONIf the engine does not operate properly,refer to the Troubleshooting Chart on page105 or consult authorized Yanmar Marinedealer or distributor.Supply the authorized Yanmar Marinedealer or distributor with the followinginformation:• Model name and serial number of yourengine• Boat model, hull material, size (tons)• Use, type of boating, number of hoursrun• Total number of operation hours (refer tohour meter), age of boat• The operating conditions when theproblem occurs:• Engine speed (min-1 )• Color of exhaust smoke• Type of diesel fuel• Type of engine oil• Any abnormal noises or vibration• Operating environment such as highaltitude or extreme ambienttemperatures, etc.• Engine maintenance history andprevious problems• Other factors that contribute to theproblem
