Troy...the needle valve assembly is probably the least precision made part of the whole engine so what's given in any manual is only a guide. Remember that an engine will start and run even if it's way too rich but if it's too lean then it'll likely just fire up then stop. It also depends on what fuel you're using. Lots of nitro (not usually a problem in Oz ) means the needle has to be opened more than with low nitro so I've never understood these suggestions about "open the needle 1 1/2 turns" without it even being said with what fuel!