2005 Speedmaster has the 865. America is still the 790. Keep in mind, prior to 2005 the Speedmaster was also 790. So ..... your dealer is correct if the bike was built prior to 2005. But shouldn't be dealing if the bike is a 2005 as the speedmaster's engine is larger. The larger 2005 Speedmaster engine generates more torque than the 790, but the 790 generates more horsepower at a higher RPM. See Triumph's web site for full specs:
SpeedmasterAmericaRegards,
