Page 292 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

Adjustment of tappet process: For tappet adjustment both valves should be in closed position when piston of
that cylinder is at TDC on compression stroke. At this time, the valve timing mark punches either on flywheel or
on Dumper pulley, should coincide with pointer. Remember piston inn one cycle reaches on TDC twice during
compression and exhaust stroke. We have to adjust the during compression stroke only. To confirm this, rotate
both to push rods by hand. If they are loose enough, piston TDC compression stroke.

You can also check this by another method by bringing the timing mark under the pointer and then rotating the
flywheel 20 degree clockwise and then anticlockwise. If rocker arm starts dancing i.e. inlet valve opens and
exhaust valve closes or vise-versa. It shows that piston is at exhaust stroke TDC position. So to get piston in
compression stroke, rotates the crankshaft by one revolution and adjust tappets.

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CITS : Automotive - Mechanic Diesel - Lesson 85 & 86