Kerosine makes a good wash medium. After cleaning and reassembling, use any good after run oil like any airtool oil, Rislone, AFT etc. Do not use WD40 or a light weight oil like sewing machine oil unless you are going to immediately run the engine. Pain old denatured alchohol also will work to clean it initially. Believe it or not, hot soapy water works very well also, just oil well immediately after cleaning.