under the seat
The proper air gap is .032 to .036 depending on spark plug brand.
Three
should be 20-50 wt harley oil but check with your dealer first..
In the compartment under the seat on the other side from the oil reserve
Nope, the fender struts on the rear fender are different so the holes won't line up.
Right side of bike by the seat is the oil tank pull out round dip stick
Honestly, if you have to ask; take it too an experienced harley mechanic. It is very easy to ruin the carb if you do not know what you are doing? Save yourself the money of buying new parts by paying too have it done correct the first time.
The spark plug gap for a 1999 H-D (Harley Davidson) is .032 to .036. The actual gap depends on the brand of spark plugs.
If you are doing an oil change it would be 2.75 quarts. That will bring it to just under the full line when cold.
That is the overflow tube. It means that the float level is too high, or there is crap in your float bowl.
1200