1. Use Cylinder Indicator (special tool #C-119, Cylinder Indicator) (2) to correctly measure the inside diameter of the cylinder bore (3). A cylinder bore gauge capable of reading in 0.003 mm (0.0001 in.) increments is required. If a bore gauge is not available, do not use an inside micrometer.
2. Measure the inside diameter of the cylinder bore at three levels below the top of the bore (4).
Start at the top of the bore, perpendicular (across or at 90ยฐ) to the axis of the crankshaft at point A (1).
3. Repeat the measurement near the middle of the bore then repeat the measurement near the bottom of the bore.
4. Determine the taper by subtracting the smaller diameter from the larger diameter.
5. Rotate the measuring device 90ยฐ to point B (1) and repeat the three measurements. Verify that the maximum taper is within specifications.
6. Determine out-of-roundness by comparing the difference between each measurement.
7. If the cylinder bore taper does not exceed 0.0127 mm (0.0005 inch) and out-of-roundness does not exceed 0.008 mm (0.0003 inch) then the cylinder bore can be honed. If the cylinder bore taper or out- of-round condition exceeds the maximum limits, replace the engine block.
NOTE: A slight amount of taper always exists in the cylinder bore after the engine has been in use for a period of time.