MAINTENANCE 16. Loosen the jam nut and turn the lash adjuster until the valve lash is correct. 21. Repeat steps 16-18. 22. Clean sealing surfaces of the cylinder head and valve cover. 17. Set the intake and exhaust valve lash to specification. 23. Inspect the condition of the valve cover bolt rubber isolators. If rubber has become hardened or cracked, replace them. 2 24. Install a new valve cover seal and install the valve cover. Torque the cover bolts to specification. Intake Valve Clearance: .006 in. (.15 mm) Valve Cover Bolts: 89 in. lbs. (10 Nm) Exhaust Valve Clearance: .009 in. (.23 mm) 25. Install the upper right-hand frame support and torque the (4) mounting bolts to specification.
18. Hold adjuster and torque the jam nut using a torque wrench w/10 mm crow’s foot adaptor. Verify clearance is still correct after tightening the jam nut. Upper Right-Hand Frame Support Bolts: 36 ft. lbs. (49 Nm) Rocker Jam Nut: 71-89 in. lbs. (8-10 Nm) 26. Reassemble vehicle by reversing this procedure. Start the engine to ensure proper valve adjustment was performed. 19. Turn the drive clutch counter-clockwise to rotate the cam sprocket 225° to the PTO (#2) Adjustment Position . PTO (#2) Adjustment Position Timing Marks at PTO (#2) Adjustment Position Compression and Leakdown Tests NOTE: This engine does NOT have decompression components.
Compression readings will vary in proportion to cranking speed during the test. Smooth idle generally indicates good compression. Low engine compression is rarely a factor in running condition problems above idle speed. Abnormally high compression can be caused by worn or damaged exhaust cam lobes. A cylinder leak-down test is the best indication of engine condition. Follow tester manufacturer’s instructions to perform a cylinder leak-down test. (Never use high pressure leakage testers as crankshaft seals may dislodge and leak) . 20. Set the PTO cylinder valve lash by placing the feeler gauge blade between the lash adjuster and valve as shown.
Measured Cylinder Compression 210-250 psi (full throttle) PTO (#2) Cylinder Leakage Service Limit: 10% (Inspect for cause if leakage exceeds 10%) 2.15 = In. / mm. = T = In. / mm. = T = T