Sierra Battery Power Pack 18-99238 for Johnson/Evinrude 3-Cylinder 55-100 HP (1968-1972), Replaces 397123

The Sierra 18-99238 Battery Power Pack is a direct-fit ignition power pack built for Johnson/Evinrude 3 cylinder outboard engines covering the 55, 60, 65, 85 and 100 HP range from 1968-1972. The power pack is the central switching component of the battery-powered CD ignition system on these engines, storing and discharging the energy that fires the spark plugs in the correct sequence. If the original power pack has failed or is showing age-related weakness, replacing it with the 18-99238 restores reliable starting and consistent spark timing without needing to rewire or modify the ignition harness.

The unit runs on a 12 volt system and uses a NiCAD battery cell composition internally, matching the original equipment design for these engines. It is sold as a single unit and is built to bolt into the same mounting location as the factory power pack, using the same electrical connections. Because it is engineered specifically for the 1968-1972 3 cylinder Johnson/Evinrude engine family listed above, it is not a universal part and should be matched to the correct year, cylinder count, and horsepower before ordering.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99238
• Voltage: 12 Volts
• Battery Cell Composition: NiCAD
• Unit Count: 1 Count
• Weight: 1.7 pounds
• Engine Fitment: Johnson/Evinrude 3 cylinder engines, 55, 60, 65, 85 and 100 HP, 1968-1972

Fitment

• Johnson/Evinrude 3 cylinder engines: 55, 60, 65, 85 and 100 HP (1968-1972)

Replaces (OEM)

• 382579
• 389549
• 389550
• 389551
• 389551L
• 397123
• 398550
• 398551
• 777647
• 9G0M
• D550
• D551
• 6CB2004
• 6CB2007
• 6CB2009
• 6CB2001
• 583579
• 580849

Frequently Asked Questions

What does the Sierra 18-99238 battery power pack fit? The Sierra 18-99238 fits Johnson/Evinrude 3 cylinder outboard engines in the 55, 60, 65, 85 and 100 HP range built between 1968 and 1972.

Is the 18-99238 a direct OEM replacement? Yes, the 18-99238 is built as a direct replacement for the original Johnson/Evinrude power pack on the applicable 3 cylinder engines, using the same 12 volt connection points.

What OEM part numbers does the 18-99238 replace? The 18-99238 replaces OEM numbers 382579, 389549, 389550, 389551, 389551L, 397123, 398550, 398551, 777647, 9G0M, D550, D551, 6CB2004, 6CB2007, 6CB2009, 6CB2001, 583579 and 580849.

What voltage does this power pack run on? It operates on a 12 volt system, matching the original Johnson/Evinrude ignition setup on the covered 3 cylinder engines.

What battery cell type is inside the 18-99238? The power pack uses a NiCAD battery cell composition, the same cell type used in the original equipment unit.

How much does the 18-99238 power pack weigh? The Sierra 18-99238 weighs 1.7 pounds.

How many units come in the package? The 18-99238 is sold as a single unit, one power pack per package.

Will this power pack work on a 4 cylinder Johnson/Evinrude engine? No. The 18-99238 is designed for 3 cylinder Johnson/Evinrude engines in the 55-100 HP range from 1968-1972 and is not intended for 4 cylinder applications.

What horsepower engines use the 18-99238? The applicable horsepower ratings are 55, 60, 65, 85 and 100 HP, all on 3 cylinder Johnson/Evinrude engines from 1968-1972.

Why would I need to replace my battery power pack? A worn or failing power pack causes inconsistent spark, hard starting, or intermittent misfires; installing the Sierra 18-99238 restores the original ignition switching function on the covered 1968-1972 3 cylinder engines.

Does the 18-99238 require any wiring modifications to install? No, it is built to connect using the same electrical connections as the original Johnson/Evinrude power pack on these 3 cylinder engines, so no rewiring is needed.