SAFARI

ENGINE

110

Fig. 22

Fig. 23

CHECKING VALVE TIMING

1. Attach suitable graduated disc to the crankshaft

pulley and mark ‘BDC’ position on the periphery

of the pulley by turning crankshaft by 180

from

‘TDC’ position. Fig. 22.

2. Remove cylinder head cover.

3. Adjust valve clearance (inlet 0.2 mm outlet 0.3

mm). Eliminate No. 1 inlet valve clearance by

inserting a 0.2 thick feeler gauge between valve

tip and rocker. Fig. 23.

4. Turn crankshaft to bring No. 1 piston to TDC

(compression stroke). In this position, valves of the

No. 4 cylinder will be overlapping.

5. Attach magnetic stand with dial gauge to the

cylinder head in such a way that the plunger of

the dial gauge rests on the spring retainer of the

1st cylinder inlet valve with a preload of about 10

mm. Position plunger on the spring retainer as

away as possible from the centre to avoid fouling

of the rocker. Adjust dial gauge pointer (bigger)

to zero and also note down the reading of the

smaller needle.

6. Turn crankshaft clockwise slowly through 360

bring No. 1 piston just to TDC II position (end of

the exhaust stroke). Do not turn crankshaft in anti-

clockwise direction to adjust TDC position.

NOTE :

Before reaching the TDC position, preloaded

plunger of the dial gauge will move along the

spring retainer of the valve. Note down dial gauge

reading when the TDC position is just reached.

7. The difference between dial gauge readings will

give valve lift. The valve timing is correct if the lift

indicated by the dial gauge is within the specified

value of 0.75 + 0.2 mm.

8. The valve timing can be counter checked by

turning the crankshaft clockwise further by 180

in order to bring No. 1 piston to BDC II position

(end of the suction stroke). Note down the dial

gauge reading when the BDC position is just

reached. The difference between this and the

initial dial gauge reading will give the valve lift in

this position.The timing is correct if the lift is within

the specified value of 4.25 + 0.3 mm.

9. Valve timing can also be ascertained by checking

the lift of the exhaust valve. To be doubly sure, it is

preferable to check the lift of the exhaust valve of

No. 4 cylinder. The valve lift at BDC I (end of power

stroke) and TDC II (end of exhaust stroke) should

correspond to specifications.

10. Valve lift readings beyond the specification

suggest wrong valve timing possibly on account

of worn out crankshaft-camshaft gears/damaged

woodruff keys/mismatched timing gears (i.e. ‘1’

mark on crankshaft gear tooth is not matched with

‘3 - 3’ mark on camshaft gear.

11. Identify the defect and rectify.