1992 ZX11C, does not smoke, running straight antifreeze, none in oil, runs good, drips out of small drain tube on bottom of airbox, white talc-like film on inside of intake tubes, plugs and cylinder not wet however intake valves do look wet, compression 145-160 all cylinders, losses about 1/3 cup coolant per week, temp normal. Notice when started cold with cap off can see coolant flowing all the time and must put cap on or will overflow after about a minute, no compression bubbles. Also fan quit working at beginning of season. Temp stays near cold when riding, at stop lights, goes up a little more, but never goes near halfway mark.

 

Bad thermostat; for starters.

(Why straight coolant? No water at all?)

 

Not quite sure what would cause coolant to get to the airbox, unless you had both a bad head gasket and bad valves..

BTW: The purpose of antifreeze is to keep the water in your system from freezeing, its the water that carries most of the heat away.

 

50/50 soft water and aluminum safe antifreeze is recommended. Pressure test the system to no more than 18psi. Good luck on the find. Welcome to KF.