Yamaha's part number for the 1998 SEROW is LIT-11616-XT-25, and the machine itself is coded XT225K. The book spans 1992 to 2000, so late-run bikes and early ones share a single reference.
That is useful when a component has been superseded. If your 1998 carries an earlier part, or a later replacement, the specification is still somewhere in the same set of tables.
The text is the factory's, unedited: assembly and disassembly in the intended order, torque values, clearance and wear limits, wiring diagrams with the values needed to test against them, and fault-finding sequences for starting, charging, fuel and ignition complaints. Confirm XT225K against your frame plate before ordering so the figures you work to are the right ones.
