Measuring, Boring and Honing Cylinder Bores

NOTE: The cylinder bore roughness has been temporarily increased from 2-4 micro m to 3-6 micro m.


The part numbers of the crankcase have not been changed.







Production breakpoint: September 1983







a Upper reversing point of 1st piston ring
b BDC of piston
c Lower reversing point of oil scraper ring

In addition of a visual checkup, in particular in the event of complaints about "high oil consumption" measuring of cylinder bores is unavoidable.

For this purpose, measure the clean cylinder bores with internal measuring instrument at measuring points, 1, 2 and 3 in longitudinal direction A (piston pin center line) and in transverse direction B.

With piston installed, the measuring point 3 is barely above piston, at BDC.







Chamfer cylinder bores after boring.

For honing, the material allowance should not exceed 0.03 mm.