Hi Kane, thats 2 great tips. Never heard of these B4. Will just add by saying that I use the 2stroke oil for pre-mix. It's thin, cheap and squezzes out well by hand. Been doing it this way for 35 years. It's always the last thing I do in race prep, so there is generally not seapage, and if there is, it just drains down through the hole (supplied with most Jap airbox designs)