i love how they shoot flames out the back, especially at night. mine used to do that too. and i think the bo bo bo is the sound of the back pressure from the exhaust when he is letting of the gas, does you cobra have a baffle in it or no? taking out the baffles make them sound louder and give them that bobo sound when not on the gas.
1985 KXT 250 Tecate - kx cylinder, kx ignition, bassani headpipe, answer silencer, v-force reeds, 38mm airstyker carb, +2 franks swinger, raptor rear shock.
1996 YSF240 Blaster - maxxed out!!!
Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting "HOLY SH-T, what a ride!"