For 2010, both the GS and its heavy-duty Adventure sibling received updated top ends. The new mill maintains the traditional 1170cc displacement and four valves per cylinder but doubles the cam count and increases valve diameter (up 3mm for the intake and 2mm for the exhaust) and lift for more peak power. Performance is increased to a claimed 110 horsepower at 7750 rpm-5 up on the old unit. The new motor revs 500 rpm higher, too, maxing out at 8500 rpm. It's stronger by several horsepower almost everywhere from 2500 rpm to that limit, especially at 5000 and 6500 rpm, where it's got about 10 more ponies. There is, however, a distinct dip between those points, where the old engine briefly claws ahead.