rev boxes

[cals400ex]

i have been thinking about getting the rev box from sparks. any problems to these or do they make a difference? i have been told the 400ex's don't want to start with these on. is this true? thanks

[oynot400]

The hard cold starts is true on the White Bros rev box. I have a Hot Box and I don't have too much trouble. I don't know if it is true or not but the box I have is suppose to be a 250x cdi box. :confused: