Why am i getting water in crankcase on 87 cr500r

Question

i am getting milky oil blowing out vent tube in crankcase when bike is running i know in a car it could be the head gasket or cracked head/block is this so on my bike also or is there something else that can cause this to happen the bike runs awsome lot of compression

Answer 1

Your head gasket broke internally or you have a crack in the head.

Answer 2

Could be a head gasket or a water pump seal. Check both

Answer 3

could be same problem as a car. leaking head gasket doesn't always affect compression drastically.  

Answer 4

The water pump o ring seal is defective.