4. Maintenance & Inspection (4) Inspecting and Replacing (2) Inspe ct ing Inner Parts of the Sea- Anticorrosion Zinc The timing for replacing anticorrosion zinc varies depending on the characteristics of the seawater and operational conditions. wat er Pump Depending on the use, the inside parts of the seawater pump deter iorate and dis- charge performance drops. At the specified interval or when the volume of seawater discharged is reduced, inspect the seawater pump in accordance with the following procedures: Inspect the zinc periodically and remove any corroded areas. Replace the anticorrosion zinc when it has been reduced to less than 1/2 of its original size.
If replacement of zinc is neglected and operation is continued wi th a small volume of anticorrosion zinc, corrosion of the seawater cooling system will occur and water leakage or parts breakage will result. The anticorrosion zinc is on the inside of the anticorrosion zinc plug which is labeled with a sticker reading: Anticorrosion Zinc. I 1 . Loosen the side cover set bolts and remove the side cover. 2. Illuminate the inside of the seawater pump with a flashlight and inspect. 3. If any of the following problems is found, disassembly and maintenance are necessary: a) Impeller blades are cracked or nicked. Edges or surfaces of the blades are marred or scratched.
(5) Replacing the Engine Oil and Lube Oil Filter (See 4.3.1 (1 )) Note: T he impe ller must be replaced (6) Cleaning the Intake Silencer Disassemble the intake silencer and clean the inside thoroughly. periodica ll y (every 1000 hrs.). b) Wear plate is damaged. Remove the cover by taking off the clamp. Clean the ele ment with a neutral de tergent. Reassemble after it is completely dry. 4. If no damage is found when inspecting the inside of the pump , reassemble the si de cover. Fit the 0-ring to the groove of the joint face before replacing the side cover . 4.3.5 Inspection Every 600 Hrs.
If a large amount of water leaks co ntinuously from the water drain pipe (1) Replac in g Fresh Water Cooling Cooling performance drops when cooling water is contaminated with rust and scale. Even if antifreeze or antirust is added, the cooling water must be replaced periodically because the properties of the agent will degenerate. To extract the cooling water , open the cooling water cocks (three places) as shown in 3.4(2). (Refer to 3.2.4 for resupplying cooling water.) beneath the seawater pump during operation, disassembly and mainte- nance (replacement of the oil seal) are necessary.
When disassembly and maintehance of the seawater pump are necessary, con- sult your Yanmar dealer or distributor. t11 r .. .:; The seawater pump turns in the counterclockwise direction, but the impeller must be insta ll ed by turning in the clockwise direction. If the impeller has been removed for any reason and must be 40