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 0 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 0 to 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 0 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.