Yes it is all adjustable..... but.......you need to take the carbs appart, if this makes you nervous then perhaps you need to get someone else to do it, if it needs doing. If your still happy with the idea then you need to learn about the why's and wherefors. An absolute must is a manual, read it until it's dog eared. Search this site for all the carb questions, there are hundreds of them! Once you have a grasp of what you want to do and, more importantly, why you want to do it, then you can get your tool kit out start to tune your carbs. The reason I recomend some caution before playing with carb settings is that: at best you can turn a sweet running engine into an unmanagable snarling spitting brute, and at worst you can wipe out your pistons/valves.
The best bit of advice i can give you when you start to fiddle is:
When you do adjust any settings on your carbs, just do one change at a time. There are so many variables that you will get lost almost straight away if you try and cut corners and change it all at once. The only exception to this rule is when you return to factory settings. The same applies to anything which is multi adjustable.
