SAFARI

486 PL ENGINE

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 45

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