Piston Fitting
WARNING: This page is about a different variant/trim than selected.
- To correctly select the proper size piston, a cylinder bore gauge, capable of reading in 0.003 mm (.0001 in.) INCREMENTS is required. If a bore gauge is not available, do not use an inside micrometer.
- Measure the inside diameter of the cylinder bore at a point 38.0 mm (1.5 inches) below top of bore. Start perpendicular (across or at 90 degrees) to the axis of the crankshaft at point A and then take an additional bore reading 90 degrees to that at point B. See Fig 2.
1 - MOLY COATED 2 - MOLY COATED 1 - FRONT 2 - BORE GAUGE 3 - CYLINDER BORE 4 - 38 MM (1.5 in) - The coated pistons will be serviced with the piston pin and connecting rod pre-assembled.
- The coating material is applied to the piston after the final piston machining process. Measuring the outside diameter of a coated piston will not provide accurate results. See Fig 1. Therefore measuring the inside diameter of the cylinder bore with a dial Bore Gauge is MANDATORY . To correctly select the proper size piston, a cylinder bore gauge capable of reading in 0.003 mm (.0001 in.) increments is required.
- Piston installation into the cylinder bore requires slightly more pressure than that required for non-coated pistons. The bonded coating on the piston will give the appearance of a line-to-line fit with the cylinder bore.