Looking at the 1999 KX125 vs 2003 KDX200/220 radiators, they look to be about the same in area/volume... the difference that stands out is that the KX has a lower crossover tube, where the KDX does not. Looking at this it would seem to me that the KX rads warm up the motor quicker and I can see why this is good for MX. The KDX rads are designed as a complete pass (kinda like a cross flow radiator in auto apps) offering ultimate temperature drop and slower warm up.
I havn't heard anyone having cooling issues with KX radiators, but I was thinking that the best thing to do was to install a restriction orifice (maybe .250") in the lower KX crossover hose.... that would keep the predominate flow going through both rads as would be more inline with the KDX design.
Thoughts?
:whoa: