To create the FireBird, V&M; starts with a stock, first-generation carbureted XX. V&M; says that "not even Honda Britain could get hold of the access codes for the new model's engine-management system...so we concentrated on the original bike, and built our own pressurized airbox." V&M; strips the stock engines and builds them up with Carrillo billet rods mounted on the stock crank, and 2mm-overbore forged pistons, raising displacement to 1198cc and compression ratio to 13:1 (from the stock 11:1.) The cylinder head is comprehensively re-ported and gas-flowed, before fitting V&M; camshafts with 1mm more lift and 20 degrees more duration. Redline increases 500 rpm to 11,750.