Kohler 3.5CFZ, 4CZ, 5CFZ, 6.5CZ Valve Adjustment, Rotating parts Can cause severe injury or death

Valve Adjustment

With overhead cam engines, each valve is spring-held in the closed position until forced open by the action of the rocker arm in contact with the camshaft. Rocker arms have adjusting screws and locknuts for adjusting valve stem-to-rocker arm clearance. Check clearance with the engine cold. See Specifications— Engine for intake and exhaust valve clearances.

WARNING

Rotating parts.

Can cause severe injury or death.

Do not operate generator set without all guards, screens, or covers in place.

Exposed moving parts can cause severe injury or

death. Keep hands, feet, hair, clothing, and test leads away from belts and pulleys when unit is running. Replace guards, covers, and screens before operating generator set.

Flying projectiles can cause severe injury or death.

Retorque all crankshaft and rotor hardware after servicing. When making adjustments or servicing generator set, do not loosen crankshaft hardware or rotor thru-bolt. If rotating crankshaft manually, direction should be clockwise only. Turning crankshaft bolt or rotor thru-bolt counterclockwise can loosen hardware and result in serious personal injury from hardware or pulley flying off engine while unit is running.

1.Remove rocker arm cover screws using a 10 mm wrench. Carefully pry rocker arm cover off cylinder cover. Wipe excess oil from components using a clean rag.

2.Expose timing belt:

a.Close seacock and drain seawater from hoses. Remove seawater pump hoses at seawater pump.

b.Remove two screws to release seawater pump bracket.

c.Remove housing enclosing ignition coil.

d.Remove seawater pump from camshaft pulley.

e.Remove timing belt cover (belt guard).

NOTE

To reduce force needed to rotate crankshaft, remove the spark plugs.

3.Using a ratchet wrench on the crankshaft nut, rotate the crankshaft clockwise (as viewed from engine end) until No. 1 cylinder is at the top of its compression stroke and the ‘T’mark on flywheel is aligned with the triangle symbol on the engine block. See Figure 3-22. The compression stroke is the period between the closing of the intake valve and the opening of the exhaust valve. The marks define the TDC (top dead center) point where both intake and exhaust valves will be closed.

4.Insert feeler gauge between rocker arm and exhaust valve for No. 1 cylinder. If necessary, adjust screw so that very slight drag is felt on the feeler gauge as it is withdrawn. Loosen the adjusting screw locknut and turn the adjusting screw to obtain the specified clearance. Retighten the locknut while holding the adjusting screw. See Figure 3-23. Recheck the valve clearance after tightening the locknut. Repeat step for intake valve of No. 1 cylinder.

5.Rotate crankshaft 360 degrees clockwise and set valve clearances on No. 2 cylinder.

6.Reassembly of timing belt components:

a.Install timing belt cover (belt guard).

b.Install seawater pump to camshaft pulley.

c.Install housing for ignition coil.

d.Mount seawater pump bracket using two screws.

e.Install seawater pump hoses to seawater pump. Open seacock.

7.With mating surfaces clean and gasket properly aligned, install rocker arm cover and screws. Remove ratchet wrench from crankshaft nut.

3-20 Scheduled Maintenance TP-5695 12/93