DYNOJET Jet Kit Yamaha YZF450 Q421

Stage 1: stock engine/filters, stock/modified pipes; about a 5% power increase, Stage 2: stock/mild modified engine, stock/modified pipes, stock/modified filters; about an 8% power increase, Stage 3: stock/mild modified engine, stock/modified pipes, individual air filters; driveability may be compromised, N/A for some motors; about a 10-15% power increase, Stage 7: race-only, high rpm, not for street use, Increases power and drivability, Fully adjustable