MTD Cub Cadet 221 HP Manual page 12

221 HP/LHP
8. Check valve lash between each valve stem and
rocker arm using a feeler gauge.
9. Intake valve lash (carburetor side) should be 0.003"-
0.005" (0.10 + 0.02mm). See Figure 2.6.
10. Exhaust valve lash (muffler side) should be 0.005-
0.007" (0.15 + 0.02mm). See Figure 2.7.
11. Use a 10mm wrench to loosen the jam nut, and a
14mm wrench to adjust the rocker arm fulcrum nut.
See Figure 2.7.
• Tighten the rocker arm fulcrum nut to close-up
the clearance between the end of the valve
stem and the contact point on the rocker arm.
• Loosen the rocker arm fulcrum nut to open-up
the clearance between the end of the valve
stem and the contact point on the rocker arm.
12. Hold the fulcrum nut with a 14 mm wrench, tighten
the jam nut to a torque of 80 - 106 in lbs (9 - 12 Nm)
using a 10 mm wrench.
13. Double-check the clearance after tightening the jam nut, to confirm that it did not shift. Re-adjust if necessary.
14. Rotate the engine through several compression cycles:
• Observe the movement of the valve gear.
• Return the piston to TDC compression stroke and re-check the valve lash to confirm consistent movement
of the valve gear, including the slight bump to the exhaust valve from the automatic compression release.
15. Clean-up any oil around the valve cover opening, clean the valve cover, replace the valve cover gasket if nec-
essary.
16. Install the valve cover, tightening the valve cover screws to a torque of 62 - 80 in lbs (7-9 Nm).
IMPORTANT: Over tightening the valve cover will cause it to leak.
17. Install the spark plug.
18. Test run the snow thrower.
19. Install the rear engine cover.
8
.004" feeler
gauge
Figure 2.6
Figure 2.7
.006" feeler
gauge