CDI Box 1YW-85540-20-00 For 1987 1988 Yamaha Big Bear YFM350FW Moto 4 YFM350ER

CDI Box for Yamaha

This CDI Box (OEM reference 1YW-85540-20-00) controls ignition timing for 1987 and 1988 Yamaha Big Bear and Moto 4 ATVs.

Overview

This CDI Box for Yamaha Big Bear YFM350FW and Moto 4 YFM350ER replaces a worn ignition unit to restore reliable spark. This CDI Box uses the OEM reference 1YW-85540-20-00 and is designed for 1987 and 1988 models. This CDI Box helps keep engine timing consistent during all riding conditions.

Built For Performance

• Replacement ignition module for Yamaha Big Bear YFM350FW and Moto 4 YFM350ER ATVs
• Matches OEM reference 1YW-85540-20-00 for proper fit and function
• Provides consistent ignition timing for reliable starting and running
• Engineered for 1987 and 1988 model year compatibility
• Solid-state construction resists vibration and heat for long service life

Fits These Machines

• for Yamaha Big Bear YFM350FW, 1987
• for Yamaha Big Bear YFM350FW, 1988
• for Yamaha Moto 4 YFM350ER

On-The-Job Use

• Restores ignition for 1987-1988 Yamaha Big Bear YFM350FW ATVs
• Replaces faulty CDI boxes for Yamaha Moto 4 YFM350ER quads
• Used with a multimeter or spark tester to diagnose no-spark conditions
• Keeps utility and trail ATVs running smoothly under varied loads

Specs At A Glance

Good To Know

Q: Is this CDI box for Yamaha machines? A: Yes, this replacement CDI box is designed for Yamaha Big Bear YFM350FW and Moto 4 YFM350ER applications.

Q: What are common symptoms of a bad CDI box? A: Common symptoms include no spark, intermittent stalling, or weak engine response. Test the ignition system before replacing the CDI box.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.