Title: Install valve train components.
Course: Small Engine Technology I (20110-I) > Section: Understanding Four-Stroke Engine Operation Theory and Components

Installation should follow manufacturer’s specifications and instructor’s guidelines and include

- inspecting and testing valve springs for squareness, pressure, and free height comparison; replacing as needed
- inspecting valve spring retainers, locks, and valve grooves
- replacing valve stem seals
- inspecting valve guides for wear; checking valve guide height and stem-to-guide clearance; reconditioning or replacing as needed
- inspecting valves; resurfacing or replacing
- inspecting valve seats; resurfacing or replacing
- checking valve face-to-seat contact and valve seat concentricity (runout), checking lapping seat-to-face; servicing seats and valves as needed
- checking valve spring assembled height and valve stem height; servicing valve and spring assemblies as needed
- inspecting and measuring camshaft bearings for wear, damage, out-of-round, and alignment; determining needed repairs.

Process/Skill Questions:

- What measuring tools are required in the installation of the valve train?
- When should valve seats/faces need reworking?
- How are overhead valve systems different from L-head valve systems?