Cylinder Diameter Check/Piston Fitting

NOTE: Measure the piston outer diameter at a right angle (90°) to the piston pin and 42 mm (1.65 inch) below dome of piston.

1. Measure the outer diameter of each piston. Measure 42 mm (1.653 in) below the piston dome at 90° to the piston pin.

Grade Sizes Without Coating

Red 1: 90.167-90.180 mm (3.549875-3.550387 inch).
Blue 2: 90.180-90.193 mm (3.550387-3.550898 inch).
Yellow 3: 90.193-90.206 mm (3.550898-3.551417 inch).

Grade Sizes With Coating Are:

NOTE: Due to skirt coating the piston size cannot be measured. Pistons are graded prior to skirt coating.

Red 1: 90.187-90.212 mm (3.550662-3.551646 inch).
Blue 2: 90.200-90.225 mm (3.551174-3.552158 inch).
Yellow 3: 90.213-90.238 mm (3.551686-3.552677 inch).

2. Measure the cylinder block piston bores 13 mm (1/2 inch) below the top of the deck.
3. Measure the cylinder block piston bores 13 mm (1/2 inch) above top of piston with piston at its lowest pint of travel in the cylinder block bore.
4. The difference between the two is the piston to cylinder bore clearance.
Clearance Limit: 0.012-0.026 mm (0.000472-0.001024 inch).
5. Select a piston to keep clearance within range.
If bore is: 90.200-90.213 mm (3.551181-3.551693 inch), Select Red piston.
If bore is: 90.213-90.226 mm (3.551693-3.552205 inch), Select Blue piston.
If bore is: 90.226-90.239 mm (3.552205-3.552716 inch), Select Yellow piston.
6. Measure the piston pin fit. Replace components as necessary.