For the jetting, you will have to use trial and error. It all depends on what elevation, and temp you habitually ride at. In AZ, we ride at about 4500 ft in 80-100 temp. My daughter's 99 CR80 (identical to the 2002 except BNG) is running a 48 pilot, 118 main, air screw two turns out, and needle in 2nd slot from top. Repack your silencer and clean the air filter before starting. Be conservative on the main jet and needle, too lean and you will grenade your engine. Stock, your bike will have a 50 pilot, 125 main, and needle in 3rd from top (unless the dealer rejetted for your alt., almost unheard of). Order a selection of jets and play until it's right.
For the spooge problem-above applies as well. A properly jetted CR80 will hardly spooge at all. You will ALWAYS have some coming out at the cyl. pipe junction as honda has never gotten that right (my '76 Els. CR125 did the same damn thing and had the same BS metal ring 25 years ago). It will be very minimal once jetted correctly, use the permatex solution the other guy suggested (what I do) or get the Atomic 22 replacement manifold with real o-rings.
Check out
www.ericgorr.com for a good guide on jetting.
Eric (not Gorr)