Servicing Top-Side Components - Toro 500 EFI Service Manual


NOTE: Support the connecting rod with rubber
bands to avoid damaging the rod or install the Con-
necting Rod Holder.
CAUTION
Do not allow the connecting rod to go down inside the
crankcase. If the rod is down inside the crankcase and
the crankshaft is rotated, severe damage will result.

NOTE: If the existing rings will not be replaced with
new rings, note the location of each ring for proper
installation. When replacing with new rings, replace
as a complete set only. If the piston rings must be
removed, remove them in this sequence.
A. Starting with the top ring, slide one end of the
ring out of the ring-groove.
B. Remove each ring by working it toward the
dome of the piston while rotating it out of the
groove.
AT THIS POINT

To service piston, see Servicing Top-Side Components
sub-section.
AT THIS POINT

To service center crankcase components only, proceed
to Removing Left-Side Components.
Servicing Top-Side
Components
VALVE ASSEMBLY
When servicing valve assembly, inspect valve seats,
valve stems, valve faces, and valve stem ends for pits,
burn marks, or other signs of abnormal wear.

NOTE: Whenever a valve is out of tolerance, it must
be replaced.
Cleaning/Inspecting Valve Cover

NOTE: If the valve cover cannot be trued, the cylin-
der head assembly must be replaced.
1. Wash the valve cover in parts-cleaning solvent.
2. Place the valve cover on a surface plate covered with
#400 grit wet-or-dry sandpaper. Using light pressure,
move the valve cover in a figure eight motion.
Inspect the sealing surface for any indication of high
spots. A high spot can be noted by a bright metallic
finish. Correct any high spots before assembly by
continuing to move the valve cover in a figure eight
motion until a uniform bright metallic finish is
attained.
Do not remove an excessive amount of the sealing sur-
face or damage to the camshaft will result. Always
check camshaft clearance when resurfacing the valve
CC033D
cover.
Water or parts-cleaning solvent must be used in con-
junction with the wet-or-dry sandpaper or damage to
the sealing surface may result.
Removing Valves

NOTE: Index all valves, springs, and cotters to their
original position when removing. When installing, all
valve components should be installed in their origi-
nal position.
1. Using a valve spring compressor, compress the valve
springs and remove the valve cotters. Account for an
upper spring retainer.
2. Remove the valve seal and the lower remaining
spring seat. Discard the valve seal.
CAUTION
CAUTION
CC130D
CC132D
81