NELSON BOUGHT HIS YAMAHA XS650 IN 2020 and it looked nothing like it does now. It was a US import XS650SE, the custom variety of the famous first Yamaha four-stroke. Although the US version of the Special is not as perky as the European model, which has something to do with carburation, compression ratios and emissions regulations, the engine in this one had been breathed upon – a lot. The original builder had turned his XS into a sprinter, as XS motors can be made to go very fast indeed, and they are tough as old boots.
For a start it had a pair of flat slide Mikuni TM carburettors. These, according to Mikuni, have smoother airflow than the previously popular XS carb upgrade, the round slide VM. The TM’s high velocity gives a stronger vacuum at the needle jet which in turn gives better throttle response. There inside the top end is a high-lift camshaft. XS650s can take all manner of performance upgrades. The clutch had been beefed up and converted to use a simple hydraulic operating system. It came with a lightly modified stock frame, while the front end came from a Suzuki Bandit 600, with the forks de-lugged and polished. The front wheel is off either a CCM640 or KTM644 with AJP hub and a CCM disc. The previous owner had swapped the old and dreadful stock shocks for some TEC items with remote reservoirs, but he felt they didn’t really suit it. The rear mudguard was heavily trimmed, and a skinny seat pan was used; the seat, being a sheet of aluminium with some foam stock to it, may not
