Yanmar 6LY2-STE — Engine Reassembly Procedure (Chapter 10, Sections 3-2.1 through 3-2.6)

For the Yanmar 6LY2-STE.

Browse Yanmar generators & specs →

Procedure

1. 3-2.1 Cylinder block: Completely clean each oil hole. After cleaning, check that no scaling remains on cylinder block.
2. 3-2.2 Tappet: Fit each tappet. Check that each tappet is fitted to the appropriate cylinder and valve (exhaust or intake). Before fitting, apply engine oil to each tappet. After fitting, check that each tappet operates smoothly.
3. 3-2.3 Piston cooling nozzle: Fit each cooling nozzle to piston. Check that nozzle end is positioned on piston head side. Also check that nozzle does not touch cylinder block. Tightening torque: 2.0 kgf-m.
4. 3-2.4 Cam shaft bearing: (1) Fit each cam shaft bearing as follows: 1) Apply lube oil to outer surface of each bearing and fitting area of cylinder block, and then press-fit metal into its position using driving tool. Check position of each oil hole; more than 2/3 area of hole should be aligned (Anti-flywheel side A=2, Intermediate position A=1.5, Flywheel side A=0.5). 2) After press-fitting, check each bearing for distortion by measuring inner diameter of bearing (approx. 57 +0.05/+0.02 mm). Note: To remove cam shaft bearing: 1. Attach plate to cam shaft bearing, and tap off bearing using copper hammer. 2. Completely clean each bearing hole on cylinder block before press-fitting each bearing.
5. 3-2.5 Crankshaft: (1) Apply engine oil to each crank journal hole of cylinder block and each block side main bearing, and then fit shaft to cylinder block. Bearings having an oil groove should be positioned on upper side (block side). Fit thrust metal so that oil grooves are respectively positioned outside. (2) Apply engine oil to each crank pin and crank journal, and fit each journal to main bearing. (3) Fitting caps: 1) Apply engine oil to both surfaces of each cap side main bearing, and then fit each main bearing to the cap. 2) Apply lube oil to bolt bearing surfaces and threaded parts of each bearing cap. Fit each bearing cap to each journal of crankshaft, and apply specified torque to tighten each bearing cap bolt (M15, 14 bolts; 24 +/- 1 kgf-m). Check that each bolt is equally tightened, and that the arrow marked on each bearing cap is positioned on the flywheel side, with matchmark on each cylinder correctly aligned. 3) Check that crankshaft rotates smoothly. 4) Measure side clearance of crankshaft using a dial indicator (side clearance of crankshaft: 0.132~0.223 mm).
6. 3-2.6 Lube oil pump: (1) Fit lube oil pump idle gear (side clearance: 0.10 to 0.30 mm; tightening torque: 11 +/- 1 kgf-m). (2) Fit lube oil pump while adjusting position of positioning pin. Secure pump by tightening 3 bolts [text cut off in source].

Source: manual:Yanmar-6LY2-STE-Service.pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.