i think 3.2 quarts if it is stock. You will have a drain plug on the oil tank that is located behind the right plastic guard. Then the oil plug on the bottom of the engine and the oil filter housing. Watch out for the oil filter housing bolt. It can be stripped out fairly easy if it has not already been been jacked up from the previous owner.

I too use some lucas in my engine. That stuff is really good. Its pricey but I only use about one bottle for every 4-5 oil changes so about 1/4 quart or less. I also started using lucas to lube the chain.