Yamaha introduced the fearsome YZ490 in 1982 as the replacement for the YZ465. Hakan Carlqvist’s factory YZ465 had won the 500cc World MX Championship in 1983, but that title subsequently eluded Yamaha riders until 1999. However, in the US, Yamaha factory rider Broc Glover took the almost equally competitive and prestigious AMA National 500cc MX Championship of 1985 riding the new YZ490.
The 1985 YZ465 featured a front disc brake, gold Takasago rims and BASS (Brake Actuated Suspension System). The 487cc production machine weighed 104kg and was fuelled by a 40mm Mikuni. It had black-painted alloy crankcases, engine covers and cylinder.
The YZ490 here is fitted with a rare, ex factory race engine with a flat-slide Keihin carb and a US-made Pro Circuit ‘Platinum’ expansion chamber exhaust. We are informed it makes 60hp at the rear wheel, over 10% more than the standard engine, and that it was raced at some point by Franco Picco, the successful Italian desert rally raid specialist.