Just a note to say I have been using Lucas Racing 100% Synthetic 20W/50 oil thru two oil changes, (change every 3,000 miles). It is made for air/oil cooled engines with oil wetted clutches including "Harley Davidson V-Twins".
Oil comes out a brown amber (went in straw amber color) and seems to run just fine...and does not break the bank at $6.99 per quart, in stock at O'Reileys/Kragen Auto Parts only a mile or so from the house.