1968 Evinrude 18 HP Fastwin Outboard Specs & Part Numbers
Introduction to the 1968 Evinrude 18 HP Fastwin
The 1968 Evinrude 18 HP Fastwin is a legendary two-stroke outboard motor revered by vintage marine enthusiasts and boaters alike. Renowned for its bulletproof reliability, simple mechanical design, and excellent power-to-weight ratio, the Fastwin was a staple of lakes and coastal waterways throughout the late 1960s. Whether you are restoring a classic aluminum fishing boat or maintaining a family heirloom, this technical guide provides the essential specifications, maintenance values, and historical context required to keep this vintage workhorse running smoothly.
Overview & Specifications
The 18 HP Fastwin strikes a perfect balance between portability and utility. Powered by a twin-cylinder, loop-scavenged powerhead, it delivers robust low-end torque capable of planing small-to-medium utilities and runabouts.
| Technical Specifications | |
|---|---|
| Manufacturer | Evinrude Motors (Division of Outboard Marine Corporation – OMC) |
| Model Year | 1968 |
| Model Numbers | 18802 (Short Shaft, Rope Start), 18803 (Long Shaft, Rope Start), 18852 (Electric Start) |
| Horsepower | 18 HP @ 4500 RPM |
| Configuration | Inline 2-Cylinder, 2-Stroke |
| Displacement | 22.0 cubic inches (360.5 cc) |
| Bore & Stroke | 2.500 in x 2.250 in (63.5 mm x 57.15 mm) |
| Fuel/Oil Ratio | 50:1 (Regular Unleaded Gasoline / TC-W3 Marine Outboard Oil) |
| Dry Weight | Approximately 79 lbs (35.8 kg) |
Note on fuel: While early OMC outboards required heavier oil ratios, the 1968 model year was engineered for a 50:1 mixture. It is highly recommended to use ethanol-free fuel (90+ octane) combined with a high-quality TC-W3 two-stroke oil to prevent fuel system degradation.
Common Maintenance & Tune-up Specs
Keeping a vintage Fastwin in peak operating condition requires periodic attention to the ignition system, fuel delivery, and cooling pump. Below are the critical tune-up parameters and component specifications.
Ignition System
The 1968 Fastwin utilizes the classic OMC “Universal Magneto” ignition system located beneath the flywheel. It consists of two sets of points, two condensers, and two internal coils.
- Spark Plug Type: Champion L77JC4 (or Champion J4C / J6C depending on running conditions; J6C runs slightly hotter to prevent fouling during prolonged trolling).
- Spark Plug Gap: 0.030 inches (0.76 mm)
- Breaker Point Gap: 0.020 inches (0.51 mm) at high point of cam.
- Ignition Coils: Dual under-flywheel coils. Inspect for cracks in the plastic casing, which is a common failure point for original vintage coils.
Fuel & Carburetion
- Carburetor Type: Float-feed single-throat carburetor with adjustable low-speed needle and fixed high-speed jet.
- Low-Speed (Idle) Mixture Adjustment: Initial setting is 1.5 turns open from gently seated. Adjust while warmed up and running in gear for optimal idle.
- High-Speed Jet: Fixed orifice (No. 54 jet standard). No user adjustment is required for sea-level operation.
Gearcase & Cooling System
Water pump maintenance is critical to prevent powerhead overheating and warping. Lower unit lubrication prevents gear wear and water intrusion damage.
- Impeller Replacement: Replace the impeller every 2 to 3 seasons. The replacement part number is generally OEM 379764 (or aftermarket equivalent Sierra 18-3005).
- Gearcase Lubricant: Standard Marine SAE 80W-90 Gear Lubricant (Hi-Vis). Do not use Type C gear lube unless it is an electric-shift model (the 18 HP is manual shift).
- Gearcase Capacity: Fill from the bottom drain hole until fluid exits the top vent hole (approximately 9 fl. oz.).
Notable Features & History
The “Fastwin” name has a long and storied history in the Evinrude lineup, dating back to the pre-WWII era. However, the 1960s iterations refined the motor into the modern, dependable configuration we recognize today.
Design and Engineering Highlights
- The OMC Universal Magneto: This ignition setup was utilized across dozens of OMC models for decades. Its simplicity meant that parts were cheap, highly interchangeable, and easy to service by DIY mechanics using basic hand tools.
- Thermostatically Controlled Cooling: Unlike earlier outboards that ran cold lake water directly through the block constantly, the 1968 Fastwin features a cylinder head thermostat. This allows the engine to reach and maintain its optimum operating temperature quickly, reducing spark plug fouling and improving fuel efficiency.
- Sound & Vibration Dampening: The 1968 model incorporates a full rubber-mount suspension system inside the lower cowl housing. Combined with a sealed, underwater exhaust outlet, it operates significantly quieter than its 1950s predecessors.
- Two-Line to One-Line Transition: By 1968, Evinrude had fully transitioned away from the dangerous pressurized two-line fuel tanks of the 1950s. The 1968 Fastwin features a modern single-line fuel system utilizing an engine-mounted, vacuum-driven fuel pump, allowing the use of standard modern portable fuel tanks.
Historical Significance
By 1968, outboard manufacturers were beginning to explore higher-horsepower, multi-cylinder designs to power larger fiberglass boats. The 18 HP Fastwin remained a vital product because it represented the upper limit of what a single adult could reasonably lift, carry, and clamp onto a transom by hand. It was the quintessential “car-topper” motor for sportsmen, resort owners, and recreational fishermen, solidifying Evinrude’s reputation for building durable, user-friendly marine engines.