about any thing the thing was built maxed out from the factory....
enough mods to make it go faster would cost more than just buying a bigger bike
i paid 3000usd for mine in 2002 i saw a r100/7 bmw for 3500usd used the other day that will
idle down the road faster so i will keep the rt stock for around the local area and try that...
as the hop up
dave ps the bmw is old enough to still be fixable by owner