Bottom End


For the latest build I decided to go with a 2008-2010 XB12 crankshaft. The 2008- cranks use a 1.5″ crankpin, larger than the 1.25″ pin of the 2003-2007 XB’s, and have larger splines on the primary side. This improved crankshaft design will drop right into the 2003-2007 XB cases with no modifications, and the stock 2008- rods are stronger than the earlier rods. I chose to upgrade to Carrillo rods since I didn’t want to risk blowing the bottom end again. The guys at Darkhorse Crankworks assembled the crank and welded the crankpin to the flywheel halves to prevent the assembly from coming out of true under high power. To set up the ignition timing properly, the 2008- cranks need a TDC mark machined in the right hand flywheel half.