Sierra Stator 18-99240 for Johnson/Evinrude 9.9-60 HP Outboards, 1977-1999, 2 Cylinder 5 Amp

The Sierra Stator 18-99240 is a 2-cylinder, 5 amp charging stator built for Johnson and Evinrude outboards. It supplies the charge coil and timer base functions needed to keep the ignition system firing correctly and the battery charging while the engine runs. The stator is a direct fit for Johnson/Evinrude 9.9, 10, 15, 20, 25, 35, 50, 55, and 60 HP engines built from 1977 to 1999, making it a common replacement for owners whose original stator has weakened, cracked, or failed an output test.

Constructed with a metal core and wound coil assembly, the 18-99240 is sized to bolt into the factory mounting location without modification. It measures 6 x 6 x 1.75 inches and weighs 1.8 pounds. Because a failing stator typically shows up as a no-charge condition, erratic tachometer readings, or a battery that will not hold a charge, replacing it with a correctly rated unit like the 18-99240 restores reliable low-end charging output across this HP range.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99240
• Cylinders: 2
• Amperage: 5 Amps
• Wattage: 60 watts
• Material: Metal
• Weight: 1.8 pounds
• Dimensions: 6 x 6 x 1.75 inches

Fitment

• Johnson/Evinrude 9.9, 10, 15, 20, 25, 35, 50, 55, and 60 HP outboards, 1977-1999

Replaces (OEM)

• 763770
• 581651
• 585087
• 584755

Frequently Asked Questions

What engines does the Sierra 18-99240 stator fit? The Sierra Stator 18-99240 fits Johnson and Evinrude outboards rated 9.9, 10, 15, 20, 25, 35, 50, 55, and 60 HP built from 1977 to 1999.

Is the 18-99240 a 2 cylinder or 3 cylinder stator? It is a 2 cylinder stator rated at 5 amps, matched to the smaller-displacement Johnson/Evinrude powerheads in the 9.9-60 HP range.

What OEM part numbers does this stator replace? Sierra 18-99240 replaces OEM numbers 763770, 581651, 585087, and 584755, so any of those part numbers on your old stator confirms this is the correct replacement.

How much does the stator weigh? The Sierra 18-99240 stator weighs 1.8 pounds.

What are the dimensions of the 18-99240 stator? It measures 6 x 6 x 1.75 inches, sized to fit the factory mounting location on the applicable Johnson/Evinrude powerheads.

What is the stator made of? The 18-99240 is built with a metal core and wound coil assembly designed for marine ignition and charging duty.

What does a stator do on a Johnson/Evinrude outboard? On these engines the stator provides the charge coil and timer base functions, supplying ignition timing signals and charging current to the battery while the motor runs.

What symptoms indicate my stator needs replacing? A failing stator on these Johnson/Evinrude engines typically causes a no-charge condition, erratic ignition timing, or a battery that will not hold a charge, which the 18-99240 is designed to correct.

Is this a genuine Sierra part or a generic aftermarket copy? This is the Sierra 18-99240 stator, sold under Sierra's own part number rather than as an unbranded generic unit.

Does the 18-99240 include mounting hardware? The listing covers the stator assembly itself (18-99240); confirm with your engine's parts diagram whether your application reuses the existing mounting hardware.

Can I use this stator on a 40 HP or 70 HP Johnson/Evinrude? No. The Sierra 18-99240 is specified for 9.9, 10, 15, 20, 25, 35, 50, 55, and 60 HP models only, so it should not be used on HP ratings outside that list.