Mm (0.0276 in.) 0.7 mm (0.0276 in.) 1.0 mm (0.0394 in.)

Mm (0.0067 in.) 0.16 mm (0.0063 in.)

Cylinder, Piston

ENGINE TOP END

Piston Ring, Piston Ring Groove Wear

• Check for uneven groove wear by inspecting the ring seat­
ing.

•The rings should fit perfectly parallel to the groove sur­faces. If not, the piston must be replaced.

• With the piston rings in their grooves, make several mea­
surements with a thickness gauge [A] to determine piston
ring/groove clearance.

Standard: Top Second Service Limit: Top Second

Piston Ring/Groove Clearance

0.03 ∼ 0.07 mm (0.0012 ∼ 0.0028 in.) 0.02 ∼ 0.06 mm (0.0008 ∼ 0.0024 in.)

Piston Ring End Gap

• Place the piston ring [A] inside the cylinder, using the pis­ton to locate the ring squarely in place. Set it close to the bottom of the cylinder, where cylinder wear is low.

• Measure the gap [B] between the ends of the ring with a thickness gauge.

Piston Ring End Gap Standard: Top Second Oil Service Limit: Top Second Oil

0.20 ∼ 0.35 mm (0.0079 ∼ 0.0138 in.) 0.20 ∼ 0.35 mm (0.0079 ∼ 0.0138 in.) 0.2 ∼ 0.7 mm (0.008 ∼ 0.028 in.)

Cylinder Inside Diameter

• Since there is a difference in cylinder wear in different di­rections, take a side-to-side and a front-to-back measure­ment at each of the 3 locations (total of 6 measurements) shown in the figure.

• If any of the cylinder inside diameter measurements ex­ceeds the service limit, the cylinder will have to be bored to oversize and then honed.

10 mm

60 mm

20 mm

Cylinder Inside Diameter
Standard: 74.000-74.012 mm (2.9134-2.9139 in.)

Service Limit: 74.11 mm (2.9177 in.)

Дата добавления: 2014-12-23