Cylinder Block - Toro Reelmaster 5100-D Service Manual

Cylinder Block

Before cleaning check the cylinder block for coolant
leaks, oil leaks or damage. Clean all parts to remove
dirt, oil, carbon deposits and water scale.
Check the cylinder block for cracks or other damage.
Check the water jacket for water scale and rust. Replace
the cylinder block if necessary.
Measure each cylinder bore size in six locations
(Fig. 98). The standard bore diameter is 76 mm
(2.9921 in.). The cylinder must be rebored and over­
sized piston and rings installed if the diameter exceeds
the standard by 0.2 mm (0.0079 in.). Examine the
cylinder bore diameter readings to determine the
amount of taper in the cylinder. If the taper exceeds 0.01
mm (0.0004 in.), the cylinder must be rebored and
oversized piston and rings installed.
IMPORTANT: If one cylinder is rebored, all cylinders
must be rebored to the same specifications.
NOTE: See the Specifications section of this chapter for
oversize finishing sizes. After machining, install the
piston and piston rings corresponding to the reworked
cylinder size.
NOTE: When the cylinder bore is worn a small amount
and only the piston rings require replacement, check for
groove wear in the upper part of the cylinder. Hone the
cylinder if necessary.
Reboring Cylinder
1. Select a piston:
0.25, 0.50 mm (0.01, 0.02 in.) oversize
2. Measure the piston diameter (Fig. 84).
3. Reboring finish dimension = (Piston O.D.) +
(Clearance) – (Honing allowance).
Clearance: 0.071 - 0.084 mm (0.0028 - 0.0033 in.)
Honing allowance = 0.02 mm (0.0008 in.)
Cylinder Block Overhaul Page 3 - 66 Rev. A
Figure 98
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Reelmaster 5100-D