Sierra 18-99395 Johnson/Evinrude 3-Cylinder Timer Base, Replaces 584804/584805/763773, Fits 1993-2001 50-70 HP Engines

The Sierra 18-99395 is a replacement timer base built for 3-cylinder Johnson/Evinrude loop charged outboard engines equipped with Quick Start and S.L.O.W. Ignition systems. The timer base is a core ignition component that controls spark timing across the powerhead, and a worn or cracked unit is a common cause of hard starting, misfires, and inconsistent idle on these engines. This timer base is molded from durable plastic to withstand the heat and vibration of the engine compartment while housing the internal ignition timing components. It is designed as a direct fit for 1993-2001 50, 60, 65, and 70 HP 3-cylinder Johnson/Evinrude loop charged engines with Quick Start and S.L.O.W. It cross-references to the OEM part numbers 584804, 584805, and 763773, so it installs in place of the original timer base without modification. At 0.8 pounds, it ships as a single ready-to-install unit. Whether you are restoring ignition performance on an aging outboard or replacing a failed timer base as part of a broader tune-up, the 18-99395 gives you an OEM-equivalent part sized and specified for this engine family.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99395
• Product Type: Timer Base
• Cylinder Count: 3
• Compatible Horsepower: 50, 60, 65, 70 HP
• Compatible Years: 1993-2001
• Ignition System: Quick Start and S.L.O.W.
• Material: Plastic
• Weight: 0.8 pounds
• UPC: 808282394288
• OEM Cross Reference: 584804, 584805, 763773

Fitment

• Johnson/Evinrude 3 cylinder loop charged engines with Quick Start and S.L.O.W.: 50, 60, 65 and 70 HP (1993-2001)

Replaces (OEM)

• 584804
• 584805
• 763773

Frequently Asked Questions

What engines does the Sierra 18-99395 timer base fit? The Sierra 18-99395 fits 3 cylinder loop charged Johnson/Evinrude engines with Quick Start and S.L.O.W. Ignition systems, specifically the 1993-2001 50, 60, 65, and 70 HP models.

What OEM part numbers does this timer base replace? It replaces OEM part numbers 584804, 584805, and 763773, so it can be installed directly in place of any of those original Johnson/Evinrude timer bases.

Is the 18-99395 an original or aftermarket timer base? The Sierra 18-99395 is an aftermarket replacement timer base manufactured to match the fit and function of the original 584804, 584805, and 763773 timer bases.

How much does the timer base weigh? The Sierra 18-99395 timer base weighs 0.8 pounds.

What material is the timer base made of? It is made of plastic, chosen to withstand the heat and vibration inside the outboard's ignition compartment.

Does this timer base work with Quick Start and S.L.O.W. Ignition systems? Yes, the 18-99395 is specifically designed for 3 cylinder loop charged Johnson/Evinrude engines equipped with Quick Start and S.L.O.W. Ignition.

What symptoms indicate a timer base needs replacement? Hard starting, misfires, and an inconsistent idle on a 3 cylinder Johnson/Evinrude engine are common signs that the timer base, such as the 18-99395, has failed or cracked.

Will the 18-99395 fit a 4 cylinder or V6 Johnson/Evinrude engine? No, the Sierra 18-99395 is built specifically for 3 cylinder loop charged 1993-2001 50, 60, 65, and 70 HP Johnson/Evinrude engines, not 4 cylinder or V6 models.

What is included when you order the 18-99395? The order includes one Sierra 18-99395 timer base, ready to install in place of the original 584804, 584805, or 763773 unit.

Can I use OEM part number 584805 to cross-reference the correct timer base? Yes, part number 584805 is one of the OEM numbers that the Sierra 18-99395 replaces, along with 584804 and 763773.