Fitting Pistons
The pistons are machined to two different weight specifications and matched to rods based on weight. All piston and rod assemblies weigh the same to maintain engine balance.
Piston and cylinder wall must be clean and dry. Piston diameter should be measured 90° to piston pin at size location shown in Fig 1 . Cylinder bores should be measured halfway down the cylinder bore and transverse to the engine crankshaft center line. See Engine - Specifications . Pistons and cylinder bores should be measured at normal room temperature, 70°F (21°C).