Title: Diagnose compression problems.
Course: Small Engine Technology II (20110-II) > Section: Diagnosing and Troubleshooting a Four-Stroke Engine

Diagnosis should include following manufacturer’s specifications and instructor’s guidelines and should include

- inspecting and testing valve springs for squareness, pressure, and free height comparison; replacing as needed
- replacing valve stem seals
- inspecting valve guides for wear; checking valve lash; reconditioning as needed
- inspecting valves for replacement
- inspecting valve seats; resurfacing or replacing
- checking valve face-to-seat contact and 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?