Briggs & Stratton MS-1055 User Manual

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PISTON, RINGS AND CONNECTING ROD INSPECTION AND ASSEMBLY
CHECKING PISTON AND RINGS
If the cylinder bore is to be resized there is no reason to
check the piston as a new oversized piston will be
used.
If the cylinder is not going to be resized and the piston
shows no signs of scoring, the piston should be
checked.
1. Check side clearance of ring grooves using NEW
rings, Fig. 3. If a 0.12 mm (0.005”) feeler gauge
can be inserted, the ring groove is worn. The
piston must be replaced.
Fig. 3 – Checking Ring Grooves
NEW PISTON RING
2. Check ring end gap, Fig. 4.
a. Clean carbon from end of rings and using the
piston, insert approximately 100 mm (3.9”)
into cylinder (below ring travel).
Ring End Gap Reject Size
Compression Rings Oil Ring
0.70 mm (0.028”)
0.70 mm
(0.028”)
Fig. 4 – Checking End Gap
CHECK END GAP
BELOW RING TRAVEL
3. Check piston pin bore, Fig. 5.
Engine Models: 432447, 522447, 582447
a. Replace if greater than 18.03 mm (0.710”) or
.01 mm (.0004”) out of round.
Engine Models: 58A447, 588447
b. Replace if greater than 21.03 mm (0.828”) or
.01 mm (.0004”) out of round.
Fig. 5 – Checking Piston Pin Bore
CHECKING PISTON PIN AND
CONNECTING ROD
1. Check piston pin, Fig. 6.
Engine Models: 432447, 522447, 582447
a. Replace if less than 17.98 mm (0.708”) or
.01 mm (.0004”) out of round.
Engine Models: 58A447, 588447
b. Replace if less than 20.98 mm (0.826”) or
.01 mm (.0004”) out of round.
Fig. 6 – Checking Piston Pin

Briggs & Stratton MS-1055 Specifications

General

Brand	Briggs & Stratton
Model	MS-1055
Category	Engine
Language	English