Quick Answer

To attach a RAM ball adapter to your Garmin fishfinder, align the adapter's pre-drilled holes with the device's mounting points, insert the included #8-32 screws, and secure them with the nylock nuts. The RAM-202-G4U includes everything you need for a solid, vibration-resistant connection.

What You Need

Before starting, gather the RAM ball adapter (RAM-202-G4U), your Garmin fishfinder, and the included hardware: three #8-32 x 5/8” Phillips pan head machine screws and three #8-32 stainless steel nylock nuts. The adapter features a 1.5" rubber ball and a flat 2.5" base with pre-drilled holes, including the universal AMPS pattern, so it fits most Garmin echo™ units without extra drilling.

Check that your fishfinder has a compatible mounting surface—usually the bottom or back of the device. If the holes don't align with the AMPS pattern, you'll need a different adapter, but the RAM-202-G4U covers the most common Garmin layouts.

Common Mistakes to Avoid

One frequent error is over-tightening the screws, which can strip the plastic threads on the fishfinder housing. Tighten until snug, then stop—nylock nuts provide the locking force, not extreme torque.

Another mistake is forgetting to use the nylock nuts. They prevent the screws from backing out due to vibration, which is critical on a boat. Always use all three screws and nuts for even pressure distribution.

Step-by-Step Installation

  1. Position the Adapter: Place the RAM-202-G4U base against the bottom of your Garmin fishfinder, aligning the pre-drilled holes with the device's mounting holes. Check that the holes line up perfectly before inserting any screws.
  2. Insert the Screws: Take one #8-32 x 5/8” Phillips screw and insert it through the adapter base into the fishfinder hole. Repeat for the other two holes. Do not cross-thread the screws—start them by hand to ensure smooth threading.
  3. Secure with Nylock Nuts: On the opposite side (inside the fishfinder), thread a nylock nut onto each screw. Tighten with a wrench or socket, but avoid over-torquing. The nylock nuts lock the screws in place; snug is enough to prevent loosening from vibration.
  4. Verify Stability: Gently wiggle the adapter to ensure it's firmly attached. The rubber ball should rotate freely, but the base must not move. If there's play, re-tighten the nuts slightly—but never exceed hand-tight plus a quarter turn.

Key Product Facts

  • RAM® Ball Adapter with #8-32 Hardware for Garmin Fishfinders: The RAM-202-G4U consists of a 1.5" diameter rubber ball connected to a flat 2.5" diameter base. This mount has pre-drilled holes, including the universal AMPS hole pattern. Included are 3x (#8-32 x 5/8” PH PD Mach Screws) and 3x (#8-32 SS Nylock Nuts) that will connect the RAM-202-G4U to the bottom of the Garmin echo™. The AMPS pattern ensures compatibility with a wide range of Garmin fishfinders, while the included hardware means you don't need to buy extra parts—just align and tighten.