0319254 EVINRUDE SCREW

Illustration 1 g00295326
Inlet and exhaust valvesDouble valve springs: (1) Outer spring Length under test force ... 35.8 mm (1.41 inch) Test force ... 176 to 195 N (40 to 44 lb) (2) Inner spring Length under test force ... 34.0 mm (1.34 inch) Test force ... 89 to 104 N (20 to 23 lb)Single valve springs (not shown) Length under test force ... 40.0 mm (1.57 inch) Test force ... 310 to 344 N (70 to 77 lb) Free length after test ... 53.4 mm (2.10 inch) (3) Recess for valve spring (4) Valve guides for the inlet valve and exhaust valve Inside diameter ... 9.51 to 9.56 mm (0.374 to 37.6 inch) Outside diameter ... 15.900 to 15.910 mm (0.6260 to 0.6265 inch) Bore diameter in cylinder head for valve guide ... 15.87 to 15.89 mm (0.625 to 0.626 inch) Interference fit of valve guide in cylinder head ... 0.03 to 0.07 mm (0.001 to 0.003 inch)Overall length of valve guide Inlet ... 57.94 mm (2.281 inch) Exhaust ... 61.1 mm (2.406 inch) Projection of valve guide above valve spring recess (3) ... 15.1 mm (0.595 inch)Note: When new valve guides are installed, new valves and new valve seat inserts must be installed. The valve guides and the valve seat inserts are supplied as partially finished parts. The unfinished valve guides and unfinished valve seat inserts are installed in the cylinder head. Then, the guides and inserts are cut and reamed in one operation with special tooling. This procedure ensures the concentricity of the valve seat to the valve guide in order to create a seal that is tight. Refer to the Disassembly and Assembly Manual for removal and installation procedures. (5) Diameter of the exhaust valve stem ... 9.43 to 9.46 mm (0.371 to 0.372 inch)Clearance of valve in valve guide ... 0.05 to 0.13 mm (0.002 to 0.005 inch)Maximum permissible clearance of valve in valve guide ... 0.15 mm (0.006 inch)Overall length of the exhaust valve ... 123.07 to 123.57 mm (4.845 to 4.865 inch) (6) Diameter of the inlet valve stem ... 9.460 to 9.490 mm (0.3724 to 0.3735 inch)Clearance of valve in the valve guide ... 0.02 to 0.10 mm (0.001 to 0.004 inch)Maximum permissible clearance of valve in valve guide ... 0.13 mm (0.005 inch)Overall length of the inlet valve ... 122.66 to 123.07 mm (4.829 to 4.845 inch) (7) Exhaust valve face angle ... 45 degreesValve seat angle ... 46 degrees (8) Diameter of the exhaust valve head ... 37.26 to 37.52 mm (1.467 to 1.477 inch)Valve depth below the cylinder head faceMinimum ... 1.28 mm (0.050 inch)Maximum ... 1.83 mm (0.072 inch)Service wear limit ... 2.08 mm (0.082 inch) (9) Diameter of the inlet valve face ... 44.86 to 45.11 mm (1.766 to 1.776 inch)Valve depth below the cylinder head faceMinimum ... 1.27 mm (0.050 inch)Maximum ... 1.60 mm (0.063 inch)Service wear limit ... 1.85 mm (0.073 inch) (10) Valve face angle of the inlet valve ... 45 degreesValve seat angle ... 46 degreesThe valve lash is the following value when the engine is hot or cold. Inlet valves ... 0.20 mm (0.008 inch) Exhaust valves ... 0.45 mm (0.018 inch)
Illustration 2 g00295327
Recess for A valve insert (11) Machine the recess in the cylinder head for the valve seat inserts to the following dimensions.Inlet Valve (A) ... 7.19 to 7.32 mm (0.283 to 0.288 inch) (B) ... 51.220 to 51.240 mm (2.0167 to 2.0175 inch) (C) Maximum radius ... 0.38 mm (0.015 inch)Exhaust Valve (A) ... 9.52 to 9.65 mm (0.375 to 0.380 inch) (B) ... 42.620 to 42.650 mm (1.6779 to 1.6790 inch) (C) Maximum radius ... 0.38 mm (0.015 inch)Note: When a new valve seat insert is installed, a new valve and valve guide must be installed. Refer to the Disassembly and Assembly Manual for removal and installation procedures.
Illustration 3 g00830794
(12) Valve seat insert (D) Included angle of the faces of the valve seat insert ... 88 degrees (E) Horizontal dimension of the chamfer ... 0.38 mm (0.015 inch) (F) Vertical dimension of the chamfer ... 0.38 mm (0.015 inch)