Well Aussie salt racing team Afflick land speed racing team went 130mph with a 100cc twin four stroke on Lake Gardiner , that 286kph. Well done boys. 

55000rpm?

Possibly feels like it on the bike but believe its 15000rpm to achieve the speed. Its a twin cam motor but dont know much about it. 

a mate of mine was up there, he was saying over 300 for some cars and 250+ for bikes