40 hp mariner outboard 2 stroke oil leak at injector pump

The bleeder screw on the side or the pump has loosened needs tightening maybe half a turn the screws purpose is to drain oil out of the clear tube that goes in to the pump if it gets air bubbles in it and can work lose on its own over time

Without seeing it in front of me its difficult to advise,i had a mercury but it wasnt oil injection so i iam not sure exactly how this injection system works but i should imagine its nothing more than a O ring thats perished or a copper washer needs cleaning with some wet and dry.I bought a new 4stroke mercury in the end because i got fed up with fuel consumption from the 80hp two stroke ,this four stroke 50hp will do about 12 14 nautical miles to roughly 6/7 litres of petrol at about 1200 rpm because iam only a sunday driver and the bumping on the waves makes my back ache unbearable,Well this is the land of fiesta /siesta /manaña --spain .Have a closer look and see where its leaking its only a mechanical pump running off the engine ,so it will have a push rod with some sort of diaphragm that pumps a tinysquirt of oil into the crankcase so it can mix with the incoming fuel ,nothing complicated