Is it safe to use carb vent / fuel lines as the oil line? Both the oil and vent lines are 1/8th in size. Its on a 1994 Polaris XLT 580. Only thing Ive noticed is the original oil lines are slightly thicker clear (now yellow, hard, tarnished) lines than the new clear fuel line I bought today to replace it. They do not go to carbs but are plugged into the engine block itself.