clay

bike was running fine but was time to rering it. bought factory parts, pistion ring,o-rings for the head,cyl.gasket. installed the parts and now exhaust is filled up with antifreeze and oil and antifreeze is mixing in the transmissiom case. any clues? I have have the head and the cyl. pressure tested and they are fine. I have taken apart three times and triple checked o-rings, gasket, and also pulled water pump seal to check the water pump shaft for any abnormal marks are scarring on the shaft. all this is after it has been kicked over several times. pull the spark plug and covered wuth antifreeze. any help would be very nice .