Service Manual

ManualsBrandsToro ManualsTrenchersToro 22972

ENGINE TOP END 5-1

Engine Top End

Table of Contents

Exploded View...................................................................................................................................................................5-2

Speciﬁcations....................................................................................................................................................................5-4

Cylinder Head....................................................................................................................................................................5-5

Compression Measurement.......................................................................................................................................5-5

Cylinder Head Assembly Removal.............................................................................................................................5-6

Cylinder Head Assembly Installation..........................................................................................................................5-6

Push Rod Removal....................................................................................................................................................5-7

Push Rod Installation.................................................................................................................................................5-7

Push Rod Inspection..................................................................................................................................................5-8

Valve Mechanism Removal/Installation......................................................................................................................5-8

Cleaning and Inspection.............................................................................................................................................5-9

Rocker Arm Inspection...............................................................................................................................................5-9

Valves..............................................................................................................................................................................5-10

Valve Clearance Inspection......................................................................................................................................5-10

Valve Clearance Adjustment....................................................................................................................................5-10

Valve Seat Inspection...............................................................................................................................................5-10

Valve Seat Repair.....................................................................................................................................................5-10

Valve Head Thickness..............................................................................................................................................5-10

Valve Stem Runout...................................................................................................................................................5-10

Valve Stem Diameter................................................................................................................................................5-10

Valve Guide Inside Diameter....................................................................................................................................5-10

Valve Spring Inspection............................................................................................................................................5-11

Cylinder, Piston...............................................................................................................................................................5-12

Piston Removal ........................................................................................................................................................5-12

Piston Installation.....................................................................................................................................................5-13

Piston/Cylinder Seizure............................................................................................................................................5-14

Piston Cleaning........................................................................................................................................................5-15

Piston Ring and Ring Groove Wear.........................................................................................................................5-15

Piston Ring End Gap...............................................................................................................................................5-16

Piston Pin, Piston Pin Hole, and Connecting Rod Wear.........................................................................................5-16

Piston Diameter........................................................................................................................................................5-17

Cylinder Inside Diameter..........................................................................................................................................5-17

Cylinder Boring and Honing.....................................................................................................................................5-17

Mufﬂer/Exhaust Pipe Installation.....................................................................................................................................5-19

Mufﬂer/Exhaust Pipe Removal.................................................................................................................................5-19

Mufﬂer/Exhaust Pipe Installation..............................................................................................................................5-19

Inspection.................................................................................................................................................................5-19