Sierra Ignition Coil 18-5181 for Johnson Evinrude 2-4 HP Outboards

The Sierra 18-5181 is an ignition coil built for Johnson and Evinrude outboard motors, supplying the spark energy the ignition system needs to fire the engine reliably. It is a direct-fit replacement coil designed to match OEM electrical specifications for the applications listed below, restoring consistent spark and easier starting on engines with a weak, intermittent, or failed original coil. The coil mounts using the same footprint as the original Johnson/Evinrude unit, allowing for straightforward removal-and-replacement service without modifying the ignition harness.

Coverage spans several small outboard horsepower classes and year ranges, and on some applications the engine requires two of these coils rather than one, so confirm the coil quantity for your specific horsepower and year before ordering. This part is sold to match the manufacturer catalog application data for the Sierra 18-5181 exactly, so buyers can cross-check their outboard's horsepower and model year against the fitment list to verify correct application.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-5181
• Category: Evinrude Outboard Ignition Coils
• UPC: 030999236807
• Weight: 0.49 pounds
• Compatible Brands: Johnson, Evinrude (OMC/BRP)
• Coil Quantity Required: 1 or 2, depending on horsepower and year (see Fitment)

Fitment

• Johnson/Evinrude 2 HP, 1971-1973 (1 coil)
• Johnson/Evinrude 2 HP, 1975-1985 (1 coil)
• Johnson/Evinrude 3 HP, 1955-1968 (2 coils)
• Johnson/Evinrude 3 HP, 1989-1990 (2 coils)
• Johnson/Evinrude 4 HP, 1969-1976 (2 coils)
• Johnson/Evinrude 4 HP, 1981-1988 (2 coils)

Frequently Asked Questions

What outboard motors does the Sierra 18-5181 ignition coil fit? The Sierra 18-5181 fits Johnson/Evinrude 2 HP outboards from 1971-1973 and 1975-1985, 3 HP outboards from 1955-1968 and 1989-1990, and 4 HP outboards from 1969-1976 and 1981-1988.

How many coils does my outboard need? Some applications for the 18-5181 need only one coil while others need two. The 2 HP applications (1971-1973 and 1975-1985) each use 1 coil, while the 3 HP 1955-1968, 3 HP 1989-1990, 4 HP 1969-1976, and 4 HP 1981-1988 applications each require 2 coils.

Is the Sierra 18-5181 an OEM or aftermarket part? The Sierra 18-5181 is an aftermarket ignition coil manufactured by Sierra to match the electrical and mounting specifications of the original Johnson/Evinrude coil for the listed applications.

What is the UPC for the Sierra 18-5181 ignition coil? The UPC for the Sierra 18-5181 ignition coil is 030999236807.

How much does the Sierra 18-5181 ignition coil weigh? The Sierra 18-5181 ignition coil weighs 0.49 pounds.

Will the 18-5181 fit a 1980 Johnson 4 HP outboard? No. A 1980 Johnson 4 HP falls in the 1977-1980 range, which uses a different Sierra coil (18-5176), not the 18-5181. The 18-5181 covers 4 HP outboards from 1969-1976 and 1981-1988.

Does the 18-5181 fit a 1995 Evinrude 3 HP outboard? No. A 1995 Evinrude 3 HP falls under the 1995-1997 range, which uses Sierra coil 18-5179, not the 18-5181.

What symptoms indicate my ignition coil needs replacement? Weak, intermittent, or no spark, hard starting, or engine misfiring are common signs of a failing ignition coil, and the Sierra 18-5181 is designed to replace a worn coil on the applicable Johnson/Evinrude outboards.

Is installation of the Sierra 18-5181 straightforward? Yes, the 18-5181 uses the same mounting footprint as the original Johnson/Evinrude coil, so it can be swapped in during standard ignition service without modifying the wiring harness.

Does the Sierra 18-5181 fit both Johnson and Evinrude outboards? Yes, the 18-5181 is listed for both Johnson and Evinrude (OMC/BRP) outboard applications in the horsepower and year ranges specified.