1. It is mandatory to use a dial bore gauge to measure each cylinder bore diameter. To correctly select the proper size piston, a cylinder bore gauge, INCREMENTS capable is of required. reading in If 0.003 a bore mm gauge (.0001 is in.) not available, do not use an inside micrometer.
2. three Measure levels the below inside top diameter of bore. of the Start cylinder perpendicular bore at (across or at 90 degrees) to the axis of the crankshaft and then take two additional reading.
3. Measure the cylinder bore diameter crosswise to the cylinder block near the top of the bore. Repeat the measurement near the middle of the bore, then repeat the measurement near the bottom of the bore.
4. Determine taper by subtracting the smaller diameter from the larger diameter.
5. Rotate measuring device 90° and repeat steps above.
6. Determine out-ot-roundness by comparing the difference between each measurement.
7. If cylinder bore taper does not exceed 0.025 mm (0.001 inch) and out-of-roundness does not exceed 0.015 mm
(0.0006 inch), the cylinder bore can be honed. It the cylinder bore taper or out- of-round condition exceeds these
maximum limits, the cylinder block must be replaced. A slight amount of taper always exists in the cylinder bore
after the engine has been in use for a period of time.
