Muffler Studs; Assembly - Briggs & Stratton Vanguard 10V300 Repair Manual

concave wear where rocker arms contact the push
rod ends. Replace the rocker arm if excessive wear
is found at either location, or if pitted, deformed, or
scored.

Muffler Studs

1. Inspect muffler studs. Replace studs if broken, bent,
or if severe thread damage is observed.
2. Replace a muffler stud as follows:
A. Retrieve the two hex nuts removed from the studs
during muffler removal.
B. Thread first nut onto stud.
C. Thread second nut onto stud until it makes firm
contact with the first.
D. Rotate inside nut in a counter-clockwise direction
until stud is loose.
NOTE: If stud is difficult to remove, apply suitable
penetrating oil to threads, and then work stud in
and out until it moves freely.
E. Remove stud from cylinder head. Remove hex
nuts from stud.
F. See Figure 58. Install new stud by hand, so that
the side with the shorter thread pattern goes
into the cylinder head, and the side with the
identification mark stays out.
G. Repeats steps 2(B) and 2(C).
H. Rotating outside nut in a clockwise direction,
tighten stud to 40-60 lb-in (4.5-6.8 N-m).
58

Assembly

1. See Figure 59. Install exhaust valve (A) assembly as
follows:
59
A. Apply a suitable engine assembly lube to the
valve stem.
NOTE: If the valves were not tagged during
disassembly, remember that the exhaust valve
always has the smaller valve face diameter.
B. From the bottom of the cylinder head, insert the
valve stem into the valve guide.
C. To distribute the assembly lube evenly around
the valve stem and guide, hand spin the valve
as it is installed. Work the valve back and forth in
the bore to verify that it slides smoothly and seats
properly.
D. Using a suitable degreaser, thoroughly clean
valve face, valve guide, and end of valve stem of
any excess assembly lube.
E. Install valve spring seat (B) down valve stem
until contact is made with machined surface of
cylinder head.
F. Install valve spring (C) over the valve stem until
seated on valve spring seat.
G. Set the valve spring retainer (D) on top of the
valve spring. Using thumbs to compress valve
spring, guide the end of the valve stem through
the larger offset hole in the valve spring retainer.
Continue pressing down until the smaller center
hole engages the valve stem groove.
H. Verify that the axis of the valve spring is parallel
to the valve stem. A slanting or leaning valve
spring will result in premature valve guide wear.
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