1. The Yanmar 4TNV86CT-PBV Engine is a reliable and powerful engine designed for use in the Z55 Gehl and 550Z Mustang Excavators. This engine is known for its durability and efficiency, making it an ideal choice for heavy-duty construction and excavation work. The Parts Catalog Manual 50940366 provides detailed information on all the parts and components of this engine, making it easy to identify and order the necessary parts for maintenance and repairs. With this manual, operators can ensure the smooth operation and longevity of their Yanmar engine-powered excavators.