Brian Gillen, MV Agusta's three- and four-cylinder platform manager, explains the primary difference between the F3 675 and 800: "On the 800 you're talking about 148 hp (at the crankshaft) versus 129 hp. So the 800 has just about the same horsepower as our F3 675 World Supersport racebike, but you have more torque than on the World Supersport bike and the same weight as the standard F3 675." The disparity between engine internals isn't overly dramatic, of course; the F3 800 has the same bore (79mm) but a longer stroke (54.3mm versus 45.9mm) and, as a result, shorter connecting rods. The camshafts are the same, but, "The valves are all titanium and with the longer stroke we had to slow down piston speeds," Gillen says. Consequently, the F3 800's rev limiter has been lowered from 15,000 rpm to 13,500 rpm. Other internal changes include a slipper clutch with 10 plates versus eight, new fuel injectors with a higher flow rate, and pistons that are lighter and also different in regard to crown shape. The compression ratio jumps from 13.0:1 to 13.3:1 as a result.