Just bleed it, over and over and if you still have air, take the stat right out. If you still get air, start thinking the worse....head gasket.
Make sure your rad cap is the highest point and machine is level. Let it warm up (not overheat), re-install the cap and then cool completely (overnight if needed) with the rad cap on, if working properly, it will take fluid from the resevior to fill the system. If it does not, you have a blockage (most likely thermostat stuck) or leak (no vacuum to suck fluid from the resevior).
A forum community dedicated to Off Road Powersport owners and enthusiasts. Come join the discussion about performance, reviews, classifieds, troubleshooting, maintenance, and more! Open to anything that slings mud Including Yamaha, Honda, Kawasaki, and Suzuki.