Re: low speed idle adjustment???
You reall need a manual for that one. The carb is adjusted to "pick-up" the advance cam at a specific point. Then there will be the low speed mixture needle but playing with that is like playing with fire: Get it too lean and you will cause engine damage.
There is also an idle stop screw on the linkage, usually near where the throttle arm from the tiller handle is located. If the idle is too low, it may be rough or the engine may stall