850691 Mercury SWITCH ASSEMBLY (POWER TRIM)

Illustration 1 g00645577
Note: Apply 8T-2998 Lubricant to the valve stems prior to installation in the cylinder head. (1) Valve springs 175-7523 Spring (Inner) Assembled length ... 60.14 mm (2.368 inch) Load at assembled length ... 118 12 N (27 3 lb) Operating length (minimum) ... 44.02 mm (1.733 inch) Load at minimum operating length ... 356 18 N (80 4 lb) Free length after test ... 71.03 mm (2.797 inch) Outside diameter ... 25.20 mm (0.992 inch) 175-7526 Spring (Outer) Assembled length ... 67.12 mm (2.643 inch) Load at assembled length ... 248 25 N (56 6 lb) Operating length (minimum) ... 51.00 mm (2.008 inch) Load at minimum operating length ... 736 35 N (165 8 lb) Free length after test ... 77.88 mm (3.066 inch) Outside diameter ... 36.30 mm (1.429 inch) (2) Valve guide Bore of installed valve guide (new parts) ... 9.487 0.025 mm (0.3735 0.0010 inch) Maximum recommended diameter of the valve guide bore ... 9.538 mm (0.3755 inch)Note: Do not use a combination of a valve and a valve guide that has a difference of 0.13 mm (0.005 inch) or more. (3) Height to top of valve guide ... 35.00 0.50 mm (1.378 0.020 inch) (4) Valve recess Inlet (new parts) ... 2.20 to 2.80 mm (0.087 to 0.110 inch) Exhaust (new parts) ... 1.20 to 1.80 mm (0.047 to 0.071 inch) Inlet (reconditioned parts) ... 2.20 to 3.29 mm (0.087 to 0.129 inch) Exhaust (reconditioned parts) ... 1.20 to 2.29 mm (0.0472 to 0.090 inch)
Illustration 2 g00640401
153-7023 Inlet Valve and 153-7024 Exhaust Valve (5) Valve face angle Inlet ... 29 1/4 1/4 degrees Exhaust ... 44 1/4 1/4 degrees (6) Valve stem diameter New valve stem diameter ... 9.441 0.010 mm (0.3717 0.0004 inch) Minimum recommended valve stem diameter ... 9.408 mm (0.3704 inch) (7) Diameter of valve head Inlet ... 47.00 0.13 mm (1.850 0.005 inch) Exhaust ... 41.81 0.13 mm (1.646 0.005 inch) (8) Minimum recommended valve lip thickness Inlet ... 2.75 mm (0.108 inch) Exhaust ... 2.05 mm (0.081 inch) (9) Overall length of valve Inlet ... 202.00 0.45 mm (7.953 0.018 inch) Exhaust ... 202.06 0.45 mm (7.955 0.018 inch)
Illustration 3 g00564825
156-4168 Valve Seat (Inlet) and 152-7582 Valve Seat (Exhaust) (10) Minimum recommended width of the valve seat Inlet ... 2.00 mm (0.079 inch) Exhaust ... 1.25 mm (0.049 inch) (11) Depth of bore in the cylinder head for the valve seat insert Inlet ... 14.00 0.10 mm (0.551 0.004 inch) Exhaust ... 13.90 0.10 mm (0.547 0.004 inch) (12) Inside diameter of valve seat insert Inlet ... 41.00 0.50 mm (1.614 0.020 inch) Exhaust ... 36.50 0.50 mm (1.437 0.020 inch) (13) Angle of valve seat face Inlet ... 30 1/4 1/2 degrees Exhaust ... 45 1/4 1/2 degrees (14) Outside diameter of valve seat insert Inlet ... 48.025 0.013 mm (1.8907 0.0005 inch) Exhaust ... 42.840 0.013 mm (1.6866 0.0005 inch)Diameter of the bore in the cylinder head for the valve seat insert Inlet ... 47.950 0.025 mm (1.8878 0.0010 inch) Exhaust ... 42.774 0.025 mm (1.6840 0.0010 inch)