Since my original post I bought and installed a set of Chinese radiators on my KX500. The installation issue of the Chinese radiators I found is the radiator mounting tabs and hose barbs don't line up with the frame mounting tabs and the bike in general. There are three solutions I found to adapting the Chinese radiators to a KX500: Adapters can be fabricated to bolt things together, tabs on the radiators can be cut off and re-welded or the mounts on the frame can be moved.
Searching this forum and Google will come up with bolt on adapter and cut off/re-weld tabs solutions. I don't recall finding any frame mods on the net up till I current KX500 build when I opted to move the frame tabs and used welded adapters to match the Chinese radiators. The solution of modding the frame mounts worked out for me as I had the means to fab/weld steel and some of the frames tabs on my project already needed to be removed for repair.
Here are some more notes on mounting the Chinese rads to a KX500:
When adapting the radiators be sure to check fitment in relation to the radiators, frame, engine, muffler, gas tank and radiator shrouds. It would be possible to fit the rads to the frame and not realized the mounting could interfere with other components besides the frame. Its a pain to check fitment with all components but worth the effort. Some of the mounting holes may line up when holding the rads to the frame. If using those existing mounts that do seem to line up its till a good idea to check overall fitment. The rads just barely fit so if they are mounted a little off hoses may not fit well, rads rub into the gas tank, ect. can occur.
The Chinese radiator hoses are generic and come in random pieces that need to be cut to fit. I spent an hour one night lining things up to make the Chinese hoses work. There was no hose long enough to reach from the top right rad to the water pump though. My solution was to buy an aluminum splice to connect two hoses to make that one long hose. When the time came to actually mount the hoses dammed if I could figure out again what needed to be cut where to make things work and splice a long hose together for the right side. In the end I said screw it and ordered an OEM hose for the right side rad to water pump.
Water hose outlets on the rads need to be moved or modded to fit the KX500. All the hoses outs fits on my project except the upper left hose that goes at 90 degrees into the cylinder head needed modifying. The hose just barely fit but the radiator hose mount interfered with the flow of water to some extent. Moving the mounts differently probably would have eliminated this problem but I am not sure. My solution was to notch the left radiator hose mount at its output to allow water to flow freely through the fitting, into the hose and on to the head while still leaving a good amount of metal to attach the hose to on the rad hose barb.
The radiator mounts that hold the radiator fin/guards in place were not bent right on the rads I bought. The angle was wrong and the distance between the mounts left the fins loosely attached. There are a few solutions to this I thought of, the mounts could be moved, the fins wired on or small bolts to hold the fins on. I decided not to mess with the mounts for the fins. I just made quick clips out of a wire that goes through the fins on the outside mounts and wraps around the fins/mounts.
