Capacitor Discharge Ignition or CDI is the ignition system on internal combustion engine by utilizing the energy stored in the capacitor is used to generate the tengangan high into the ignition coil so that the output voltage with a high coil will produce a spark at the spark plug. The spark plug is a device on the motor gasoline functioned to make stepping Sparks (spark) between the spark plug electrode gap inside the combustion chamber, so that the mixture of air and fuel burning. This research was conducted on a 125 cc motorcycle 4 steps to know how timing ignition motor performance against using BRT I-MAX and spark plug Denso Iridium. Dynamometer testing conducted on 4000 – 10000 RPM for testing power and torque. As for the fuel consumption test conducted at a speed of +/-40 km/h with a rate of fuel 150 ml. Of research results, the spark sparks best variation I-MAX BRT CDI with spark plug Denso Iridium because sparks constant with temperature of 8500 – 9000 K. greatest Torque on the variation of the CDI BRT I-MAX Denso Iridium spark plugs with the standard round 4668 RPM with 12.276 N.m. of torque power of 10.2 HP at RPM 6827 rounds with the variation of the CDI and Coil standard standard. As for low fuel consumption on the variation of the CDI BRT I-MAX with Standard Plugs of 52.6 km/liter.