Nalby, it depends, I have had this thing in so many pieces before, so my case is different, but if you are able to get the cowl off easily, I would suggest checking the tappets quite regularly while it is still new. They take a while to bed in. I would also want to make sure the top cylinder valve train is getting sufficient lube. Pull a spark plug or two and see if they are burning ok, a nice tan color is best but with 20:1 oil ratio, I would doubt you get anything but sooty black plugs...if you hear a squeak noise from any valve guides, you need to lube it. A gallon is around 4 liters in metric so yeah, thats ok I suppose....