Specifications

11LOCKED FOR PRINTING – SELECT SECT. NEEDED >
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Models 540000, 610000
• Top Compression Ring – 0.030” (0.76 mm)
• Center Compression Ring – 0.030” (0.76 mm)
• Oil Rings – 0.040” (1.0 mm)
Fig. 4
3. Check piston pin bore, Fig. 5. Replace piston if
worn beyond reject dimension or 0.0005” (0.01
mm) out of round.
Piston Pin Bore Reject Dimension
• Models 290000 – 351000 – 0.674” (17.12 mm)
• Model 380000 – 0.711” (18.06 mm)
• Model 540000 – 0.828” (21.03 mm)
Fig. 5
Inspect Piston Pin and Connecting Rod
1. Measure piston pin, Fig. 6. Replace pin if worn
beyond reject dimension or 0.0005” (0.01 mm)
out of round.
Piston Pin Reject Dimension:
• Models 290000 – 351000 – 0.672” (17.07 mm)
• Model 380000 – 0.708” (17.98 mm)
• Model 540000 – 0.826” (20.98 mm)
Fig. 6
2. Check connecting rod bearings, Fig. 7.
NOTE: Undersize (0.020”) connecting rods are
available for use on a reground crankpin
journal on some engines. See IPL for
availability. If crankpin bearing is scored or
worn replace the connecting rod.
Piston Pin Bearing (1) Reject Dimension
• Models 290000 – 351000 – 0.674” (17.12 mm)
• Model 380000 – 0.711” (18.06 mm)
• Model 540000 – 0.828” (21.03 mm)
Crankpin Bearing (2) Reject Dimension
• All Except Model 540000 – 1.461” (37.12 mm)
• Model 540000 – 1.658” (42.11 mm)
Fig. 7
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Assemble Piston and Connecting Rod
1. Lubricate parts with engine oil. Assemble #1
piston to connecting rod, Fig. 8.
2. Arrow, notch or casting mark on piston must
face flywheel side, inset Fig. 8.
• The designation “OUT 1” or the number ‘‘1”
on the connecting rod must face PTO side
(opposite arrow on piston).
• Install piston pin locks with needle nose
pliers.
For Briggs & Stratton Discount Parts Call 606-678-9623 or 606-561-4983
www.mymowerparts.com