Honda Engines | GX240 Owner's Manual Download or purchase Honda Engine owners' manuals for the GX240. HONDA GX240 TECHNICAL MANUAL Pdf Download. GX240 • GX270 • GX340 • GX390 (UT2/RT2) Technical Manual NTRODUCTION Honda engines are designed for minimal maintenance. When maintenance is required, the task is kept simple by providing convenient maintenance access and procedures. Honda engines use proven engine technology and design innovations to make them highly reliable engines.