My 1981 cb650 c has a bit of oil leak coming out of the last Left cyclinder on top it looks like its coming through the exhaust that connects to the Cyclinder not sure and when i touch the exhaust of the last left exhaust pipe its not has hot as the other 3 pipes . I suspect the cyclinder is not firing well and compression cud be less and the oil is coming our from there . has any one had this problem and or what does the experts say is this typical of these honda bikes.