Checking and adjusting start of fuel delivery Checking start of delivery Figs. 1 and 2 1 2 3 For the purpose of checking the start-of-delivery setting, an “OT” (= TDC) mark and a scale from 10 ... 50 _ before TDC are engraved on a disc Б fitted in front of the torsional vibration damper. The scale marks are read against a pointer А fitted to the crankcase. In order to enable the engine to be rotated manu- ally during adjustments, there is a plate with a cen- tral hexagon driver В fitted to the front of the crankshaft pulley (barring device). 1 An engine cranking device (special tool) may be mounted also at the inspection hole of the flywheel housing.
For this purpose, the speed pickup to- gether with the plate is to be previously detached. 2 Fig. 3 There is another scale engraved on the flywheel which can be read through an inspection hole in the flywheel housing but access may be difficult. The scale should be used for readjusting the pointer after the vibration damper has been re- moved or replaced. In other words, before the vibration damper with the scale disc is installed, the engine should be positioned at “OT” (top dead centre) by means of the scale on the flywheel. The pointer should then be aligned such that its measuring edge exactly coincides with the “OT” mark on the scale disc. 3 Fig.
4 To avoid incorrect readings, always look past the notch on the flywheel housing and straight towards the flywheel centre. The marking on the graduated scale must be on the imaginary “notch - flywheel centre” line. 4 24