44 486 PL ENGINE P Fig. 98 Fig. 97 Valve Seats of Valves : Check gauge dimension of valve seat in cylinder head with respect to the specified valve. Replace valve seat inserts if they are worn out beyond specified limit. Fig. 97 & 98 Support cylinder head suitably & cut exhaust and inlet valve seat with a 450 cutter. Fig. 99 CAUTION : Valve seat must be absolutely faultless and without any chatter marks. If necessary, lap valve seats to a smooth and even finish by using suitable hand pump grinder, a lapping paste and valve itself. Valve Seat Inserts Replace valve seat inserts, if they are found to be worn out beyond specified limits. Removal : Use a suitable boring machine for removing valve seat inserts from cylinder head. Bore old inserts thin (about 0.5 thickness) & then pry it out. Alternatively use a suitable turning tool to cut an annular grove into valve seat insert and then pull it out with a suitable puller. CAUTION : Avoid damaging machined cylinder head mating surface, place soft protective sheet metal under supports of puller. Measure valve seat insert bore in cylinder head. If necessary rebore to next over size. NOTE : If boring & prying is done carefully without damaging bore in cylinder head, Fitment of an over size valve seat insert will not be necessary. Clean valve seat insert and its bore in cylinder head thoroughly. Fig. 99
RkJQdWJsaXNoZXIy MTIwNTUz