OK, lets start with the filter. Is it a stock filter, or is it some after market filter? The honda filter is best for paper filters. The cheaper paper filters are hit and miss.
Ok, so if you have the choke pulled out and the idle cam engages, your idle will be around 2500 rpm till you start to push the choke in. It might be a bit higher or lower. You also can't go too much by the stock tach, for fine readings. So to recap, choke out engages fast idle cam and the rpm will be around 2500 or so.
If you have a slow idle return when the choke is off, that usually means the bike is a bit lean. Easiest way to check is to pull the plugs and look at the insulator tip base. If it is really white, it is lean. Try to turn the fuel screws on the corresponding carbs out 1/4 turn and see how it is. Once idle improves some, then sync the carbs and do the final tune then using a more accurate tach.
The ride IS the adventure. The destination is just to get gas!