Ambassadeur USABASS 4600C 9903

Overhaul Guide: Abu Garcia Ambassadeur USABASS 4600C (Foot Number 9903)

The Ambassadeur USABASS 4600C (9903) is a special edition released in March 1999, designed to celebrate American bass fishing heritage. Built on the classic 4600 frame, this model is a "Thumb Bar" version of the 4000 series, featuring a narrow spool and a high-speed gear ratio. It is highly regarded for its ergonomic design and its ability to handle modern bass techniques like jerkbaits and topwater.

The "9903" designation indicates it has the Instant Anti-Reverse (IAR) system. Maintenance on this model requires a delicate touch with the IAR bearing to ensure the handle remains rock-solid without slipping.

Tools and Lubricants Required

• Precision Screwdrivers: Flathead and a small Phillips.

• Wrench: 10mm for the handle nut.

• Cleaning Solvent: Isopropyl alcohol or a professional-grade degreaser.

• Grease: Deuthlon Reel Gear Grease.

• Oil: Deuthlon Reel Oil (Cast Lube).

1. External Disassembly

1. Handle Side: Remove the handle nut locking screw and the 10mm nut. Slide off the handle, the spring washer, and the star drag.

2. Side Plate: Loosen the three knurled thumb screws. Carefully pull the right-side plate away from the frame.

3. The IAR Sleeve: You will see a polished stainless steel sleeve on the drive shaft. This sleeve fits into the IAR bearing inside the side plate. Slide it off and set it aside for cleaning.

4. Spool Removal: Slide the spool out. Note the two small centrifugal brake blocks on the spool pins; ensure they don't fall off during the process.

2. Deep Cleaning the 1999 Drive Train

By 1999, Abu Garcia was using high-precision brass gears and the "Ultracast" spool design (where the bearings are inside the spool).

• The Gear Stack: Remove the main gear and the drag stack. The USABASS model typically features a multi-disc drag. Clean the metal washers until they are polished. If the drag washers are worn, consider upgrading to Carbontex for smoother pressure.

• The IAR Bearing: Located inside the side plate. Use a cotton swab dampened with solvent to clean the internal rollers. Warning: Never pack this bearing with grease; it must remain surgically clean or lightly oiled to prevent handle slip in cold weather.

• Level Wind: Remove the worm shaft and the pawl. Because the 4600C level wind is non-disengaging (moves during the cast), any grit here acts as a physical brake on your spool.

3. Precision Lubrication with Deuthlon

Using Deuthlon products allows this 1990s classic to perform with the speed and smoothness of a modern finesse reel.

Deuthlon Reel Gear Grease:

• Main and Pinion Gears: Apply a light, translucent coat to the gear teeth. Deuthlon Reel Gear Grease is perfect for the 4600C's high-speed gears because it reduces the "buzz" or vibration felt during a fast retrieve.

• Clutch Linkage: Apply grease to the thumb bar mechanism and the sliding surfaces of the yoke.

• Yoke Posts: Lightly coat the two posts the pinion yoke slides on for a effortless engagement.

Deuthlon Reel Oil (Cast Lube):

• Spool Bearings: The 4600C features the Ultracast system with bearings inside the spool. Apply one drop of Deuthlon Reel Oil to each bearing. This oil is essential for maximizing casting distance with lighter bass lures.

• IAR Sleeve (Critical): Apply an extremely thin film of oil to the outside of the sleeve. This protects against corrosion while ensuring the IAR rollers bite instantly.

• Worm Shaft: Apply one drop to the worm gear. Using oil instead of grease on the level wind significantly reduces the mechanical load during the cast.

4. Reassembly and Tuning

1. Level Wind: Reinstall the worm shaft and line guide. Ensure the pawl is seated correctly in the tracks.

2. Internal Assembly: Replace the pinion gear, yoke, and main gear assembly.

3. Sleeve and Plate: Slide the IAR sleeve onto the drive shaft. Align the side plate so the IAR bearing slides smoothly over the sleeve.

4. Final Fastening: Secure the three thumb screws. Reinstall the star drag and handle.

5. Tensioning: Adjust the cast control knob until the side-to-side play in the spool just barely disappears.

Technical Performance Note

The Ambassadeur USABASS 4600C is a fantastic bridge between vintage durability and modern ergonomics. By using Deuthlon Reel Gear Grease and Deuthlon Cast Lube, you are removing the internal friction that usually slows down these late-90s models. This maintenance ensures your USABASS remains a crisp, fast-casting tool that can handle everything from weightless worms to deep-diving cranks.