I just bought my first 650. It is a 75 and I am pretty stoked on it. I do have a 76 cb550 and love the old bikes. The CB is pretty stock and I want to heavily modify the 650. I am going through the bike now and noticed that the foam on the filters for the carbs are gummy with a red sticky goop. It is like if you took jam and melted it down. I am assuming this is oil. The engine is modified to a 750 cc but stock other than that which I know of. Any and all information on this is greatly appreciated. I am also wondering if the filters can be cleaned and how so. The foam seems to be in good condition minus the goop.