Factory settings are typically rediculously rich to cover the company's ass legally. If they gave you an engine that was too lean, and you blew it up without adjusting anything, you could blame them. Since you don't want to cough up the $20.00 for a temp. gauge, keep this in mind:
Water boils at 212 degrees F. So spit should sizzle within a couple seconds. Better yet, would be an eye dropper full of water, since it puts out water drops instead of bubbly saliva. Use the high speed needle to get that in range. The problem is that any temperature over 212 will get the job done (you could be at 300 and not know -- that is where the gauge comes in handy).
Once you have done that, pinch and hold the fuel line closed to make sure that the engine dies within 3-5 seconds. Lean to make it die sooner, richen to make it die later. Make sure you get this right. If this needle is too rich, you could be running your high speed needle too lean (starving your engine for lubrication) without knowing it.
After all thats set get your idle gap set to factory, and then adjust to make it as high as possible without engaging the clutch (without making the car move).
Once all that is done, re-check everything, since a change to one needle affects the others. Keep playing with it, until temps are in range (boiling spit), the engine dies in the right ammount of time, the idle is set properly and you should see smoke from low-mid rpms when accelerating.
EDIT: While you do need to make small adjustments (1/12th turn at a time -- 1 hour on a clock), don't be afraid to be well away from factory settings. The weather in Japan or Italy or wherever your engine was built is probably different from where you are at. You are making adjustments for YOUR situation, don't worry about what works right for anyone else.
There is no ballpark settings that people can recommend, you just need to play with it until you get it right. Unless of course, you can do the math to determine your altitude, barometric pressure, temperature, humidity, glow plug brand and type, fuel brand, type, and percentage, and manufacturing tolerances of your engine/carb/plug, clutch setup, body openings, air filter oil, etc. If you can pull that off, NASA may be hiring.
