NOTICE: For cylinder barrel inspection, refer to the Direct Drive Overhaul Manual.
B. Refer to Table 4 for an analysis of cylinder inspection results and corrective action. Record
all findings on a copy of the 100-Hour, and 400-Hour Engine Inspection Checklists as
records of inspection and any corrective action in the engine logbook.
2. Visual Cylinder Inspection
A. Examine the cylinder and cylinder head (Figure 1) thoroughly for cracks, leaks, rust, pitting
and/or damage. Replace a damaged, rusted, pitted, leaky or cracked cylinder per instructions
in this chapter.
B. Look for loose or damaged crankcase thru-studs and cylinder hold-down studs. Replace with
appropriate oversize studs per Appendix A.
C. Look for loose or damaged spark plug Heli-Coil
®
inserts. If a loose or damaged Heli-Coil
®
is
found, replace the Heli-Coil
®
per the “Heli-Coil
®
Replacement” procedure in this chapter.
D. Look for cracked or broken fins and baffles (Figure 1). If a cooling fin adjacent to the exhaust
port flange is cracked, a 3/16 in. diameter hole can be drilled as a stop, under the following
conditions:
• The end of the crack is at least 1/4 in. (6.35 mm) from the base of the metal; or
• The cracked area can be removed from the fin, provided the maximum removal is no more
than one-half the total fin width; or
• No burrs or sharp edges are in evidence; or
• The minimum fillet at the root of the removed portion of the fin has a 1/4 in. (6.35 mm)
radius, and the minimum corner at the top of the fin adjacent to the removed portion has a
1/2 in. (12.7 mm) radius; or
• There is no more than one crack per fin and its depth is not more than 1/4 in. (6.35 mm)
from the base of the metal, and a fin stabilizer is used to reduce vibration and prevent
further deepening of the crack.
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