I'd recommend adding
SeaFoam to the crankcase. Follow directions on the can, as to amount (1-1.5 oz. of
SeaFoam per quart of oil), and when it changes to black (could be as soon as five minutes of run time!), change oil and filter. This will dissolve any carbon/varnish deposits within the crankcase, and the the transmission, both at the same time. That will get rid of any crud within, allowing you to start fresh, a clean engine and transmission, with good oil.
For economy,
Shell Rotella T6 is your best option: ~$27/gallon, at Wal-Mart; 'synthetic' (actually a highly refined dino oil, but it performs as a full synthetic), can be run for 7,000 miles, easily, without worry; 5W-40, so it can run perfectly, at nearly any temperature; it can be used in any engine, diesel or gasoline, being rated for both, SM rated for cars (I run it in everything: car, truck, two bikes, lawnmowers, snowblower, even my air compressor), so you only need one oil for everything! There is very little in the way of Friction Modifiers within
Rotella T6 -- some, but not enough to meet the government's requirements to put the energy star symbol on the bottle, not enough to affect a clutch, either. Do a Google search on "Rotella T6 motorcycle", and you will get plenty of feedback on its use. Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII