0351618 EVINRUDE SCREW, Elec.cover (DR & W Models only)

Illustration 1 g01345407
Cross section of cylinder head
(1) Valve spring Naturally aspirated engines The installed length of the valve springs ... 35.17 mm (1.3846 inch)The load for the installed valve springs ... 335 N (75 lb)Turbocharged engines The installed length of the inlet valve springs (high ratings) ... 35.17 mm (1.3846 inch)The load for the installed inlet valve springs ... 335 N (75 lb)The installed length of the inlet valve springs (low ratings) ... 36.17 mm (1.4240 inch)The load for the installed inlet valve springs ... 312 N (70 lb)The installed length of the exhaust valve springs (all ratings) ... 36.17 mm (1.4240 inch)The load for the installed exhaust valve spring ... 312 N (70 lb)Turbocharged aftercooled engines The installed length of the valve springs ... 36.17 mm (1.4240 inch)The load for the installed valve springs ... 312 N (70 lb) (2) Valve spring recess (3) The finished valve guides Inside diameter of valve guide ... 9.000 to 9.022 mm (0.3543 to 0.3552 inch)Outside diameter of the valve guide ... 13.034 to 13.047 mm (0.5131 to 0.5137 inch)Interference fit of valve guide in cylinder head ... 0.007 to 0.047 mm (0.0003 to 0.0019 inch)Length of Valve guide ... 51.00 to 51.50 mm (2.018 to 2.027 inch)Projection of the valve guide above the valve spring recess (2) ... 12.35 to 12.65 mm (0.486 to 0.498 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. The guides and inserts are then 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 Disassembly and Assembly for removal and installation procedures. (4) Exhaust valve Diameter of the exhaust valve stem ... 8.938 to 8.960 mm (0.3519 to 0.3528 inch)Clearance of valve in valve guide ... 0.040 to 0.062 mm (0.0016 to 0.0024 inch)Overall length of the exhaust valve ... 128.184 to 128.634 mm (5.0466 to 5.0643 inch)The face of the exhaust valve is recessed below the cylinder head by the following amount.Naturally aspirated engines ... 0.55 to 0.81 mm (0.0217 to 0.0319 inch)Service limit ... 1.06 mm (0.042 inch)Turbocharged engines ... 1.55 to 1.81 mm (0.0610 to 0.0713 inch)Service limit ... 2.06 mm (0.0811 inch)Turbocharged aftercooled engines ... 1.55 to 1.81 mm (0.0610 to 0.0713 inch)Service limit ... 2.06 mm (0.0811 inch) (5) Inlet valve Diameter of the inlet valve stem ... 8.953 to 8.975 mm (0.3525 to 0.3533 inch)Clearance of valve in valve guide ... 0.025 to 0.069 mm (0.001 to 0.0027 inch)Overall length of the inlet valve ... 128.838 to 129.288 mm (5.0724 to 5.0901 inch)The face of the inlet valve is recessed below the cylinder head by the following amount.Naturally aspirated engines ... 0.60 to 0.85 mm (0.0236 to 0.0335 inch)Turbocharged engines (high rating) ... 0.60 to 0.85 mm (0.0236 to 0.0335 inch)Service limit ... 1.09 mm (0.043 inch)Turbocharged engines (low rating) ... 1.60 to 1.85 mm (0.0630 to 0.0728 inch)Turbocharged aftercooled engines ... 1.60 to 1.85 mm (0.0630 to 0.0728 inch)Service limit ... 2.09 mm (0.0823 inch) (6) Exhaust valve face angle from the horizontal axis Valve face angle ... 30 degreesValve seat angle ... 30 degrees (7) Diameter of the exhaust valve head ... 41.51 to 41.75 mm (1.634 to 1.643 inch) (8) Diameter of the head of the inlet valve ... 46.28 to 46.53 mm (1.8220 to 1.8319 inch) (9) Angle of the inlet valve face from the vertical axis Valve face angle ... 45 degreesValve seat angle ... 45 degreesThe valve lash is the following value when the engine is cold: Inlet valves ... 0.20 mm (0.008 inch)Exhaust valves ... 0.45 mm (0.018 inch)
Illustration 2 g00809016
Recess for the valve seat insert
(10) Machine the recess in the head for valve seat inserts to the following dimensions. Recess for Inlet Valve Seat for Naturally Aspirated Engines and high rated turbocharged engines (A) ... 9.84 to 10.04 mm (0.3874 to 0.3953 inch) (B) ... 47.820 to 47.845 mm (1.8827 to 1.8837 inch) (C) Maximum radius ... 0.38 mm (0.015 inch)Recess for Exhaust Valve Seat for Naturally Aspirated Engines and high rated turbocharged engines (A) ... 9.84 to 10.04 mm (0.3874 to 0.3953 inch) (B) ... 42.420 to 42.445 mm (1.6701 to 1.6711 inch) (C) Maximum radius ... 0.38 mm (0.015 inch)Recess for Inlet Valve Seat for low rated turbocharged engines and turbocharged aftercooled engines (A) ... 10.84 to 11.04 mm (0.4268 to 0.4346 inch) (B) ... 47.820 to 47.845 mm (1.8827 to 1.8837 inch) (C) Maximum radius ... 0.38 mm (0.015 inch)Recess for Exhaust Valve Seat for turbocharged engines and turbocharged aftercooled engines (A) ... 10.84 to 11.04 mm (0.4268 to 0.4346 inch) (B) ... 42.420 to 42.445 mm (1.6701 to 1.6711 inch) (C) Maximum radius ... 0.38 mm (0.015 inch)