Kawasaki WORKHORSE 250 (2003) [98/322] Piston cylinder clearance

4-34 ENGINE TOP END

Cylinder and Piston

Piston/Cylinder Clearance

•

Subtract the piston diameter from the cylinder inside di-

ameter to get the piston/cylinder clearance.

Piston/Cylinder Clearance

Standard: 0.020 ∼ 0.047 mm (0.0008 ∼ 0.0019 in.)

Piston Ring and Ring Groove Wear

•

Check for uneven groove wear by inspecting the ring seat-

ing.

The rings should fit perfectly parallel to groove surfaces.

If not, replace the piston and all the piston rings.

•

With the piston rings in their grooves, make several mea-

surements with a thickness gauge [A] to determine piston

ring/groove clearance.

Piston Ring/Groove Clearance

Standard Service Limit

Top: 0.02 ∼ 0.06 mm 0.16 mm

(0.0008 ∼ 0.0024 in.) (0.0063 in.)

Second:

0.02 ∼ 0.06 mm 0.16 mm

(0.0008 ∼ 0.0024 in.) (0.0063 in.)

If the p iston ring groove clearance is greater than the ser-

vice limit, measure the ring thickness and groove w idth as

follows to decide whether to replace the rings, the piston

or both.

Piston Ring Groo ve Width

•

Measure the piston ring groove width.

○

Use a vernier caliper at several points around the piston.

Piston Ring Groove Width

Standard Service Limit

Top: 0.81 ∼ 0.83 mm 0.91 mm

(0.0319 ∼ 0.0327 in.) (0.0358 in.)

Second: 1.21 ∼ 1.23 mm 1.31 mm

(0.0476 ∼ 0.0484 in.) (0.0516 in.)

Oil: 2.51 ∼ 2.53 mm 2.61 mm

(0.0988 ∼ 0.0996 in.) (0.1028 in.)

If the width of any of the two grooves is wider than the

service limit at any point, replace the piston.