Both bikes are all-rounders, a solo sports ride or two-up tourer. But they do look dated alongside a Fazer. Who cares? The original retro XJ600S is the best used bargain because its frame mounted fairing is so efficient.
Naked XJ600Ns were super-cheap in 2001, and your offer should reflect this fact. Often owned by older riders who like the relaxed riding position and the simplicity of air-cooling and eight valves, look for a low mileage, Datatagged Diversion with a hugger and a Scott oiler fitted to extend chain life. Both frame and swingarm are steel, and suspension is basic.
Fully faired Diversions are rare. Some paint schemes, such as the dark green and blue, make a Diversion look duller than the red or maroon. Hard riders should look for late versions with twin 320mm front discs rather than the earlier single disc. Poor starting may be a failing diaphragm fuel pump, replaced by an electric pump. Mikuni CV carb diaphragms are expensive, but servicing is cheap and the original finish is excellent.
Although those crossover exhaust header pipes are stainless, the rest of the system rots, so examine header-to-can connections. Brake caliper seals are also notorious for creeping out past their pistons, causing pad drag and disc wear. Spin both wheels with the bike on its centre stand to check for dragging.
With a membership of over 5000, the Dutch Yamaha Diversion Club promotes these 120mph slant fours more effectively than the factory through its English language website www.ydcn.nl.