Ultimate Definitive Service Manual & Supplement for Yamaha SECA 750 XJ750RH-RK and XJ750K Motorcycle, 1981-1983 edition

Ultimate 1981-1983 Yamaha SECA 750 & XJ750K Service & Repair Manual

Restore and maintain your vintage Yamaha with the most comprehensive technical resource available. This professional-grade workshop manual combines the primary Service Manual with the essential Supplement to cover the entire 1981-1983 Yamaha XJ750 series, including the high-performance SECA 750 models and the refined XJ750K.

Whether you are a dedicated collector performing a frame-off restoration or a DIY mechanic handling seasonal maintenance, this manual provides the factory-level precision required for the sophisticated engineering of the XJ750 line.

Model Coverage & Identification

This documentation is specifically tailored for the following North American and international models:

• XJ750RH Seca (1981)
• XJ750RJ Seca (1982)
• XJ750RK Seca (1983)
• XJ750K (1983)

To ensure you are using the correct data for your specific bike, refer to the starting serial numbers documented in this manual:

• Yamaha XJ750K: Starting Frame/Engine Serial Number 22T-000101

Deep Technical Insight for the XJ750 Series

The Yamaha XJ750 was a pioneer in motorcycle technology, featuring the Yamaha Induction Control System (YICS) and, on SECA models, an advanced Computerized Monitor System. This manual explains these systems in detail, which is critical because standard universal repair guides often overlook these Yamaha-specific innovations.

What is Included in this Manual:

• Full Engine Mastery: Complete teardown and assembly instructions for the 748cc DOHC air-cooled inline-four. Includes precise tolerances for the crankshaft bearings, cam chain tensioner adjustments, and valve clearances.
• YICS & Carburetion: Specific procedures for synchronizing the Hitachi carburetors and managing the YICS (Yamaha Induction Control System) for optimal fuel efficiency and throttle response.
• Advanced Electronics: Detailed troubleshooting for the Computerized Monitor System found on the SECA 750, including the fuel meter sensor, battery fluid level sensor, and the complex safety interlock circuits.
• Chassis & Anti-Dive Suspension: The SECA 750 models featured a sophisticated anti-dive fork system. This manual provides the only reliable schematics and service steps for maintaining this specialized hydraulic-mechanical link.
• Shaft Drive Maintenance: Detailed service for the final gear case and universal joints, ensuring the smooth power delivery that defined the XJ series remains reliable.
• Wiring Diagrams: Includes high-resolution wiring schematics for both the XJ750K and the XJ750RH, essential for tracing ignition, charging, and lighting faults.

Why This Manual is Essential

The XJ750 series utilizes a mix of English and Metric hardware and features unique safety systems like the side-stand switch and brake fluid level warnings. This manual eliminates the risk of damaging rare components by providing the exact tightening torques and specialized tool requirements (such as the valve seat cutter or the T.C.I. checker) needed for a professional-grade repair.

Stop searching through forums for conflicting torque specs. Get the official factory data and keep your Yamaha SECA or XJ750K in showroom mechanical condition.