Yamaha SR400 / SR500: Cafe Racer Donor Guide
Arguably the most cafe-friendly Japanese donor ever made — light, simple, and served by a dedicated SR-only aftermarket. The single-cylinder ceiling on outright drama is lower than a multi, but nothing is easier or cheaper to start with.
Engine: Air-cooled SOHC 2-valve single, dry-sump. SR500: 499cc, 31.5 hp @ 6,500 rpm. SR400: 399cc (kept under Japan's licence tier)
Years: SR400 (Japan) 1978–2021; SR500 (US 1978–81, Europe 1978–83)
Weight: ~348 lb / 158 kg dry
Final drive: Chain
Value: Rough/non-running projects roughly $1,300–$1,800; a good running example roughly $2,500–$4,000. (A new-in-crate SR500 famously made $12,000 — an outlier, not a normal comp.) Directional only — not an appraisal.
Common problems
- Valve-train wear on higher-mileage engines — a tick that grows with rpm points to clearances or a worn valve train.
- Carburettor gumming from stale fuel is very common given how many have sat for years.
- Braking is under-specified by modern standards — a single front disc throughout, with a rear drum on most years and markets — so plan to upgrade it regardless of build.
What to check before you buy
- Match engine and frame VIN numbers.
- Look under the engine and around the headers for fresh oil staining (seals).
- Distinguish a valve-train tick (rises with rpm) from a deep bottom-end knock through warm-up.
- Check chain and sprocket condition.
- Confirm it starts reliably in a few kicks with choke — repeated failed kicks signal tuning/compression trouble, not just technique.
Sources
Facts on this page are drawn from:
Values are directional guidance from classified and auction aggregates, not a verified appraisal — always check current sold comps for your market before buying or selling.