Briggs & Stratton Vanguard 430000, User Manual

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8
Figure 1
2. Oil ring may be removed by hand by spiraling
top scraper into center ring groove, then into
top groove and off piston. Repeat for bottom
scraper, then remove expander.
3. Disassemble piston from connecting rod
using Piston Pin Fixture #19419.
NOTE: Piston pin stop ( A , Figure 2) must be
removed from support ( B ) when disassembling
piston and connecting rod.
4. Insert threaded driver ( C ) through piston pin
from FRONT side of piston and thread into
pilot.
5. Place piston with driver onto support with
arrow on piston facing up.
6. Press out piston pin.
Figure 2
Inspect 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 ( A , Figure 3). If a 0.0045 in. (0.11
mm) feeler gauge can be inserted, the ring
groove is worn. The piston must be
replaced.
Figure 3
2. Check ring end gap (Figure 4).
3. Clean carbon from end of rings and insert
approximately 1.0 in. (25 mm) into cylinder.
Figure 4
4. Check piston pin bore (Figure 5).