oil filling primary cover
engine oil tank level just below top mark and primary oil filled to just below level did about about 130 mile round trip , check oil tank and level just above low , checked primary chain and oil poured out of level screw , the primary side oil seal has gone with engine oil filling primary side . Replaced seal twice now and seals look okay < no damage to see > but cant understand why this is happening , have breather on inlet rocker cover and RGM one way breather valve on engine breather to tank .