The Crank snaps on the Flywheelside... its the torsion from the big and heavy fleewheel that does it.
I dont have a portmap of the pink kit.
Here is something to help you do the math: http://www.af1racing.com/store/Scrip...idproduct=1165
75mph is a piece of cake at less than 12000rpm.
ToraTora, the D50B and the AM-6 are really totaly difrent engines mate, if your into racing and the rulles alouw you to swap the engine i would drop a AM-6 in your bike.