97156 Mercruiser STUD

Change the Coolant
At operating temperature, the engine coolant is hot and under pressure.Steam can cause personal injury.Check the coolant level only after the engine has been stopped and the fill cap is cool enough to touch with your bare hand.Remove the fill cap slowly to relieve pressure.Cooling system conditioner contains alkali. Avoid contact with the skin and eyes to prevent personal injury.Use all cleaning solutions with care.
Never add coolant to an overheated engine; allow the engine to cool first.Check the specific gravity of the antifreeze coolant solution frequently in cold weather to ensure adequate protection.If the machine is to be shipped to, or stored in, an area with temperatures below 0°C (32°F), the cooling system must be protected to the lowest expected outside temperature.All water is corrosive at engine operating temperatures. The cooling system should be protected with a 3% to 6% concentration of cooling system conditioner at all times regardless of the concentration of antifreeze.Do not use Caterpillar cooling system conditioner with Dowtherm 209 Full-Fill coolant. Follow the instructions provided with Dowtherm 209 Full-Fill coolant.
Coolant should be drained and replaced every 2000 service hours or 1 year. However, when liquid cooling system conditioner is added every 250 service hours as recommended, the drain period can be extended to 4000 service hours or 2 years.A 3% to 6% concentration of Caterpillar cooling system conditioner can be maintained by adding conditioner as specified.Premix antifreeze coolant solution to provide protection to the lowest expected outside temperature. Pure undiluted antifreeze will freeze at -23°C (-10°F).Use clean water that is low in scale forming minerals. Do not use softened water.Filling at over 20 liters (5 U.S. gallons) per minute can cause air pockets in the cooling system.When the engine is shipped from the factory, its cooling system is protected to -28°C (-20°F), with permanent-type antifreeze.Operate with a thermostat in the cooling system year-round. Overheating will occur without a thermostat. 1. Raise the radiator cap access cover. 2. Loosen the radiator coolant cap slowly to relieve pressure, and remove the cap. 3. Open the drain valve under the radiator and allow coolant to drain into a container.4. Close the valve. 5. Remove the drain plug on the engine block and allow coolant to drain. Install the plug. 6. Fill the cooling system with a cleaning solution. Use a commercially available cleaner or 1 kg (2 lbs) sodium bisulfate per 38 liters (10 gal) water as a cleaner.7. Start and operate the engine for 1/2hour.8. Stop the engine and drain the cleaning solution.9. Flush the system with water with the engine stopped.10. Close the drain valve. Fill the system with a neutralizer. Use a commercially available neutralizer.11. Operate the engine for ten minutes.12. Stop the engine and drain the neutralizer.13. Flush the system with water with the engine stopped.14. Close the drain valve.15. Fill the system with clean water and operate the engine for five minutes.16. Drain the cooling system and close the drain valve.17. Repeat the flushing procedure until the draining water is clear.18. Add the coolant solution. See "Refill Capacities."Also add .95 liters (1 quart) of coolant system conditioner.19. Start the engine and operate it with the radiator cap off, until the thermostat opens and the level stabilizes.20. Maintain the coolant level 15 mm (.62 inch) below the top of the fill tube.21. Install the radiator cap.Engine Valve Lash
Measure Valve Lash (Clearance)
To prevent possible injury, do not use the starter motor to turn the flywheel.Hot engine components can cause burns. Allow additional time for the engine to cool before measuring valve clearance.
Measure the valve lash with the engine stopped. To obtain an accurate measurement, allow at least 20 minutes for the valves to cool to engine cylinder head and block temperature.
If the valve clearance is within 0.08 mm (.003 in) of the nominal clearance given, adjustment is not required. If the clearance is not within these limits, set the clearance as given in the chart. Refer to the Service Manual or your Caterpillar dealer for the complete valve adjustment procedure.