I waited 43 years before I purchased my first Harley and please believe me I´m very happy with my xl883, however I´m expieriencing some oil/gas residue on the rear exhaust heat shield after riding several miles. Also I noticed on two occasios what appeared to be oil/gas pooling on top of the right engine cover. Directly under the air cleaner. Is this a common problem and what is causing it? Thanks Scott