HEXA

ENGINE 133 7. Remove the valve springs. 8. Remove the valve guide seals and take out the spring seats. 9. Remove the valves. (Inlet and Exhaust) 10. Remove the cylinder head gasket. INSPECTION : A. Cylinder Head : Checking Cylinder Head Mating Surface : 1. Using a straight edge and feeler gauge, check evenness of cylinder head parting surface with crank case. If unevenness exceeds specified values, replace cylinder head. 2. Permissible unevenness of cylinder head mating surface-0.030 mm (Length wise). 3. Permissible unevenness of cylinder head mating surface-0.015 mm (Cross wise). NOTE  Cylinder head top and bottom surface re- machining in service is not permitted. B. Valves : 1. Check valve leakages by pouring gasoline on valve head. Gasoline must not seep past valve seat. 2. Valves with burnt heads, excessive scoring and wear on stem should be replaced. 3. Check valve seat run out with respect to valve stem. If it exceeds specified limit replace valve. No attempt should be made to straighten bent valves. 4. If valve is free from any other defects except worn out seat, then only it can be re-matched on valve grinding machine as follows:  Clamp valve on grinding machine jaws as close as possible to valve head.  Adjust grinding angle on graduated scale to achieve correct valve seat angle.  Feed valve slowly towards grinding wheel until wheel just touches valve head.  Grind at low feed until valve seat is just clean all around. NOTE  After grinding valve head thickness should not be less than 0.85 mm. C. Valve Guides : 1. In case of valve stem sticking in valve guide bore or Excessive clearance between them, remove valve guide From cylinder head using drift (Part No.2868 5890 06 05). 2. Check the condition of valve guide oil seals. 3. Check valve guide bore diameter in cylinder head and if necessary, ream valve guide bore in cylinder head to next over size. 4. Install matching size valve guide in cylinder head using drift (Part No. 2868 5890 06 05) and spacer (Part No. 2653 5890 06 01).