Motorcycle Repair: 1980 Honda 900, crankcase oil, vent tube

Question
After riding the cycle,there is a leak of red fluid coming from one of several black hoses down the side on the right close to where the clear battery overflow line runs down. It looks like the black line may run up to the engine part right before the cylinders. It looks like transmission fluid from a car, kind of. Also, is it normal for the gear linkage to make some rattling whenever I shift gears. I put in 75w-90 gear oil and it seems to have quieted it down? Thank you so much for your help. I am kind of a novice on this stuff.

Answer
Tom,Im not sure this will help but here goes. The transmission oil and the clutch oil and crankcase oil is all the same. Drain all the oil out of the engine and change the filter. Put in the correct amount of 10w40 motor oil. The oil will fill the transmission as well as the crankcase. What may be happening is the oil is blowing out the vent tube because its the wrong oil.The gear lube will be to heavy and not go through the pump well enough and may cause early brg failure.