Technical data

Overhaul

Crankshaft

20. Remove the gear wheel. Use a prong puller. Clean

the crankshaft. Measure the crank- and main bearing

pins. The eccentricity must not exceed 0.06 mm

(.002362 in.) and the taper 0.05 mm (.001969 in.).

Should these values be exceeded, the crankshaft

must be ground to a suitable underdimension, see un-

der “Technical Data”.

Pistons, cylinders

21. Check the wear on pistons, piston rings and gudg-

eon pins. Replace these if necessary. Use a cylinder

indicator gauge to measure the cylinder bores. The

measurement of the biggest wear is made immediate-

ly beneath the edge of the upper dead center and

crosswise the engine. The measurement of the small-

est wear is made at the lower dead center. As to the

cylinder diameter, see “Technical Data”. Use a mi-

crometer to measure the pistons. Piston diameter,

see under “Technical Data”.

22. Insert a new piston ring into the cylinder and

measure the piston ring gap. As to the measurement,

see under “Technical Data”. If necessary increase the

gap, using a special file.

23. Measure the clearance of the piston rings in the

piston ring grooves. Regarding the measurement, see

under “Technical Data”.

24. Use piston ring pliers to install the piston rings.

The marking of the rings (TOP or the mark of the

manufacturer) must be turned upwards. The height of

the upper compression ring: 1.75 mm (.068898 in.)

The height of the lower compression ring: 2.00 mm

(.07874 in.). Turn the piston rings so that the gaps are

turned 120° from each other.