I bought a 83 12a Got it running after rebuilding the carb but when I went to put water in the radiator it locked up the engine. I drained the radiator and undid the plug water drain plug on the motor but no luck. I paid $100 for the car thinking I could get it running and I did. Straight body, needs paint but with good interior. Would water leaking into the housings be a seal or O ring or maybe housing killing crack?

 

Most common source of water getting into combustion chambers is from electrolosys actually eating a hole thru the aluminum rotor housing near a spark plug hole. Pull out the leading or lower two spark plugs and see which one water leaks out of. It is also possible to have leakage from coolant passages due to failed rotor housing 'o' ring or warped housing from severe overheating. And yes it is possible to hydrolock a rotary engine just as easily as a piston engine.