Finding Top Center Position for No. 1 Piston

Finding Top Center Position for No. 1 Piston

Note: Refer to the Disassembly and Assembly for your machine for the removal of components.

Table 1

Required Tools
Callout	Part Number	Description	Quantity
A	299-9126	Crankshaft Turning Tool	1

1. Remove the valve mechanism cover from the engine.

 

2. Install Tooling (A) on the engine's flywheel housing. Use Tooling (A) in order to rotate the engine. Refer to Illustration 1.

3. Rotate the crankshaft clockwise when you face the front of the engine. Rotate the crankshaft until the pushrod for the inlet valve of the rear cylinder begins to tighten.

4. Rotate the crankshaft further by 1/8 of a turn in a clockwise direction. Insert a suitable lever between the rocker arm and the valve spring cap of the No. 1 inlet valve. Open the inlet valve. Put a spacer that is approximately 5 mm (0.2 inch) thick between the valve stem and the rocker arm.

5. Slowly rotate the crankshaft in a counterclockwise direction until the piston makes contact with the open valve. Make a temporary mark on the damper or the pulley. The temporary make must align accurately with the tip of the pointer.

6. Rotate the crankshaft in a clockwise direction by one or two degrees. Remove the spacer that is between the valve stem and the rocker arm. Rotate the crankshaft by 1/4 of a turn in a counterclockwise direction. Put a spacer that is approximately 5 mm (0.2 inch) thick between the valve stem and the rocker lever of the No. 1 inlet valve.

7. Slowly rotate the crankshaft clockwise until the piston makes contact with the open valve. Make another temporary mark on the damper or the pulley. The temporary mark must align accurately with the tip of the pointer.

8. Make a temporary mark at the center point between the two marks on the damper or the pulley. Remove the other two marks. Rotate the crankshaft by 1/8 of a turn in a counterclockwise direction. Remove the spacer between the valve stem and the rocker arm.

(1) Pointer
(2) Pulley

(3) Top center mark 

(1) Pointer (2) Pulley (3) Top center mark

9. Slowly rotate the crankshaft in a clockwise direction until the mark on the damper of the pulley (2), which was made in Step 8, aligns with the tip of the pointer (1). The No. 1 piston is now at the top center on the compression stroke. Refer to Illustration 2 and Illustration 3.