| Component | Specification |
|---|---|
| Production Years | 1987 – 1995 |
| Engine Oil | SAE 10W-40 / 20W-50 (3.5 L) |
| Front Tire | 100/90-19 57H |
| Rear Tire | 150/90-15 74H |
| Battery | YB16L-B |
| Spark Plug | NGK DPR7EA-9 (0.8 – 0.9 mm gap) |
The Kawasaki VN 15 (VNT50A-A), often referred to as the ‘Vulcan 88’, holds a significant place in motorcycling history as the first mass-produced V-twin motorcycle engine to exceed 1,400cc. When it debuted in 1987, its 1,470cc displacement effectively launched the ‘displacement wars’ among cruiser manufacturers, proving that Japanese engineering could dominate a segment traditionally held by American manufacturers.
Engineering Highlights
At the heart of the VNT50A-A is a liquid-cooled, 50-degree V-twin engine. Unlike many of its contemporaries, Kawasaki utilized hydraulic valve lash adjusters, a feature that significantly reduced maintenance requirements by eliminating the need for periodic valve clearance adjustments. Power is delivered to the rear wheel via a low-maintenance shaft drive system, emphasizing its role as a long-distance touring cruiser.
Maintenance Specifications
Lubrication System
For optimal engine longevity, MotoSpecsLab recommends SAE 10W-40 engine oil meeting API SE, SF, or SG standards for temperate climates. In hotter environments, 20W-50 is preferred. The total oil capacity is 3.5 liters. Regular oil changes are critical for this large-displacement engine to maintain the integrity of the hydraulic lifters.
Electrical & Ignition
The ignition system relies on NGK DPR7EA-9 spark plugs. It is vital to verify the electrode gap is set between 0.8 and 0.9 mm to ensure consistent combustion. The electrical system is supported by a YB16L-B battery, providing the necessary cranking amps to turn over the massive 1.5L pistons.
Tires and Handling
The VNT50A-A utilizes a staggered wheel setup: a 19-inch front for stability and a 15-inch rear for that classic cruiser aesthetic. Recommended tire pressures are 2.0 bar (28 psi) for the front and 2.0 bar (28 psi) for the rear when riding solo. If carrying a passenger or heavy luggage, the rear pressure should be increased up to 2.5 bar (36 psi).
Expert Verdict
The Kawasaki VN 15 VNT50A-A remains a robust platform for enthusiasts of classic Japanese cruisers. Its over-engineered internals and shaft drive make it a reliable companion, provided the cooling system and lubrication are maintained to modern standards. It is a true milestone in cruiser evolution.