Sierra Timer Base 18-99414 for Johnson/Evinrude 4 Cylinder Cross Flow Engines 65-140 HP (1985-1998)

The Sierra timer base 18-99414 is a replacement ignition timing component engineered for Johnson/Evinrude 4 cylinder Cross Flow outboard engines built without Quick Start. The timer base controls ignition timing advance as the throttle is opened, working in conjunction with the engine's ignition system to deliver correct spark timing across the RPM range. Because the timer base is a wear item subject to constant mechanical actuation from the throttle linkage, it is a common source of hard starting, rough idle, misfiring, or poor acceleration when it wears out or its contacts degrade.

This timer base is designed as a direct-fit replacement for the original Johnson/Evinrude timer base on covered 4 cylinder Cross Flow powerheads, restoring correct ignition timing behavior without modification to the surrounding ignition or throttle linkage components. It is intended for outboards ranging from 65 HP through 140 HP built in the 1985-1998 model years that use the Cross Flow 4 cylinder block without the Quick Start feature.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99414
• Product Dimensions: 8 x 5 x 3 inches
• Weight: 0.7 pounds
• Fitment: Johnson/Evinrude 4 Cylinder Cross Flow engines without Quick Start
• Horsepower Range: 65, 80, 85, 88, 90, 100, 112, 115, 120, 125, 140 HP
• Model Years: 1985-1998
• OEM Cross Reference: 763783, 583376, 582041, 581812, 583127, 583128
• UPC: 808282394455

Fitment

• Johnson/Evinrude 4 Cylinder Cross Flow engines without Quick Start, 65-140 HP, 1985-1998

Replaces (OEM)

• 763783
• 583376
• 582041
• 581812
• 583127
• 583128

Frequently Asked Questions

What engines does the Sierra 18-99414 timer base fit? The Sierra 18-99414 timer base fits Johnson/Evinrude 4 cylinder Cross Flow outboard engines without Quick Start, covering 65, 80, 85, 88, 90, 100, 112, 115, 120, 125, and 140 HP models from 1985-1998.

Will this timer base work on a Quick Start equipped engine? No. The 18-99414 timer base is designed for Johnson/Evinrude 4 cylinder Cross Flow engines without Quick Start; engines equipped with Quick Start require a different timer base.

What OEM part numbers does 18-99414 replace? The Sierra 18-99414 timer base replaces OEM Johnson/Evinrude part numbers 763783, 583376, 582041, 581812, 583127, and 583128.

How much does this timer base weigh? The Sierra 18-99414 timer base weighs 0.7 pounds.

What are the dimensions of the 18-99414 timer base? The 18-99414 timer base measures 8 x 5 x 3 inches.

What symptoms indicate a worn timer base needs replacement? Hard starting, rough idle, misfiring, and poor acceleration on a Johnson/Evinrude 4 cylinder Cross Flow outboard can indicate a worn timer base like the one replaced by Sierra 18-99414.

Is the Sierra 18-99414 a direct replacement for the factory timer base? Yes, the 18-99414 is a direct-fit replacement for the original Johnson/Evinrude timer base on covered 4 cylinder Cross Flow engines, requiring no modification to the throttle linkage or ignition system.

Does the timer base include mounting hardware? The dossier for the Sierra 18-99414 timer base does not specify included mounting hardware; it is sold as the timer base component.

What horsepower range does this timer base cover? This timer base covers 65 through 140 HP Johnson/Evinrude 4 cylinder Cross Flow outboards, specifically 65, 80, 85, 88, 90, 100, 112, 115, 120, 125, and 140 HP.

What model years is the 18-99414 timer base compatible with? The 18-99414 timer base is compatible with 1985-1998 model year Johnson/Evinrude 4 cylinder Cross Flow engines without Quick Start.

Is this part specific to Johnson or Evinrude, or both? It fits both Johnson and Evinrude branded 4 cylinder Cross Flow outboards without Quick Start within the listed HP and model year range, as both brands shared this engine platform.