Link to pic of radiators:
http://home.earthlink.net/~drnspode/images/RADIATORS002.jpg
The top hose of each radiator appears to go above the thermostat and are open all the time.
If sitting on the bike, left radiator bottom connection goes to bottom of water pump where I presume is the infeed of the water pump.
Out of the top of the water pump housing is the hose going to the bottom left of the thermostat. (Open only to the smaller 1/2" hose to the bottom left side of the right radiator when cold).
All three ports of right radiator are free flowing in all directions.
Bottom of right radiator is connected to right side of engine. (opposite side as waterpump).
All hoses are 3/4" except the bottom right output of thermostat housing to bottom left of right side of radiator) 1/2"
Dang, I hope that all makes sense....
From what Lou and I have discussed, his 250 and my 400 are very different in the way they are piped......