Engineering Highlight: The Yamaha XT 600 2KF (1987–1990) is widely regarded by enthusiasts as the ‘purest’ iteration of the XT series. Unlike its successors, the 2KF retained the long-travel suspension (255mm front/235mm rear) and a kickstart-only mechanism, making it significantly lighter and more off-road capable than the later, electric-start 3TB models. It represents the final era of Yamaha’s uncompromising dual-sport philosophy.
| Specification | Data |
|---|---|
| Model Range | Yamaha XT 600 – 2KF (1987–1990) |
| Engine Oil | SAE 20W-50 API SE/SF (2.1 L) |
| Front Tire | 90/90-21 54S |
| Rear Tire | 120/80-18 62S |
| Tire Pressure (F/R) | 1.5 bar / 1.5 bar (1.8 bar loaded) |
| Battery Type | YB3L-A |
| Spark Plug | NGK DPR8EA-9 (Gap: 0.8–0.9 mm) |
Technical Review: The 2KF Engineering Philosophy
At the heart of the 2KF lies the legendary 595cc SOHC four-valve single-cylinder engine. This unit features a dry-sump lubrication system, where the oil is stored in the frame backbone to aid cooling and maintain ground clearance. The 2KF is distinguished by its ‘big valve’ head and the YDIS (Yamaha Dual Intake System), which uses a primary Teikei carburetor for low-end response and a vacuum-operated secondary for high-RPM power.
The chassis engineering of the 2KF is centered around an aluminum swingarm—a premium feature often swapped for steel in later cost-cutting versions. This reduces unsprung weight, allowing the Monocross rear suspension to track terrain with exceptional precision for a machine of its era.
Maintenance Guide & Best Practices
Lubrication System
Because the 2KF utilizes a dry-sump system, checking the oil level requires a specific procedure. Start the engine and let it idle for several minutes to allow the scavenge pump to return oil to the tank. Check the dipstick immediately after shutting off. Always use a high-quality 20W-50 mineral or semi-synthetic oil to protect the air-cooled top end.
Ignition and Spark
The NGK DPR8EA-9 is the standard heat range plug. Ensure the gap is set precisely between 0.8mm and 0.9mm. Given the kickstart-only nature of the 2KF, a fouled plug or incorrect gap will significantly increase starting effort. We recommend inspecting the plug every 6,000 km.
Chassis and Tires
The 21-inch front wheel provides excellent roll-over capability for off-road obstacles. Maintain a pressure of 1.5 bar (22 psi) for general use. If carrying luggage or a passenger, increase the rear pressure to 1.8 bar (25 psi) to prevent carcass deformation and overheating.
Editor’s Verdict
The Yamaha XT 600 2KF remains a benchmark for reliability and mechanical simplicity. For the modern collector or vintage enduro rider, it offers a tactile, analog experience that modern EFI-equipped bikes struggle to replicate. Proper maintenance of the oil circuit and valve clearances ensures this machine will easily surpass the 100,000 km mark.