Two identifiers, and both belong on your parts list: the boat is BXT1900B-BAP, the manual is LIT-18616-04-41.
One manual, six boats
Yamaha issued this volume for the 252SD together with the 252S, 252SE, 252XE, AR250 and SX250, and kept it current for the 2024 through 2026 model years. That breadth is a feature when you are diagnosing a shared system, and a reason to double-check the model code when you are not.
The manual gives factory disassembly and reassembly order, published torque and clearance data, service limits for judging wear, complete wiring diagrams, and symptom-led diagnostic procedures. Periodic maintenance is laid out by hours and season, including the layup and recommissioning work a boat in a cold climate needs.
Written for technicians, so it expects a torque wrench and a multimeter rather than a feel for it.
