high rev box

[330Jake]

ive heard stuff about high rev cdi boxes making your motor hard to start when cold. i have a curtis sparks high rev cdi and i dont have any problems startint in any weather. can some body tell me why

[dork]

that was with the 400ex's, most companies sold rebadged xr250 dirt bike cdi's that operate on ac voltage unlike the 400ex cdi which operated primarily off dc volts. so with the xr cdi you need to spin the motor for a bit to get the cranking ac volts up to operate the cdi, vs. the 400ex cdi which would send spark as soon as it had 12v dc and cranking rpm. the sparks modified 300ex cdi uses the stock 300ex cdi and just drills out the rev limiter circuit.

[gotwarrior]

My buddy has a rev box on his 400 ex and it startes just fine. Like now when we are haveing cold days it take a few for it to start.