My 600 boils out water no matter what i do, i fill the radiator with water and then the overflow by the time i get done riding for about an hour or 2 it boils over and when i check everything the overflow is damn near dry and the radiator is down a good couple inches. I don't think the bike is burning the water cuz i runs like a champ.I have the fan wired to a switch and even if i leave it on it will still get hot riding around. I dont know if the radiator cap is bad or pump or if my radiator is clogged. I put a new thermostat in it and the pump looked good when i took it off. Any ideas to fix it would be great thanks.

 

stop during your ride and see if you can tell where the fluid is leaking out. check your radiator hoses, thermostat housing, radiator for signs of leaks. check your oil level, is it rising? if you're burning it, it should be making some greyish smoke.
you're on the right track thinking it could be your cap, not holding pressure, also probably the cheapest to replace. radiator could be clogged, pump impelar loose on the shaft, bad head gasket or cracked head.
i dont know where the fluid would be going without completely filling the resevoir, unless there is a leak somewhere, or is getting burned.

 

I agree, if no white/gray smoke then you should be able to smell the coolant as it leaks out. I would take off the upper and lower hoses off of the radiator and stick a garden hose in either hole and see what kind of flow you have going through the radiator. Then start the bike and see what kind of flow is coming out of the pump. Don't run your bike for long this way. Did you look at your oil level and color? I'm thinking either low flow through the radiator or bad water pump.

 

its boiling out of the resevoir not in the oil either, bike burns a little oil but thats all thats smoking no antifreeze or anything, lol

 

just kinda werd its boiling out the resevoir, and the resevoir is also low? the res drain is almost at cap height...
you sure thats the only place its draining overboard?
i'd try the garden hose trick, see how the radiator is flowing.