I have been out of the hobby for the last 15 years and always flew 2 strokes in the past. I just acquired my first 4-stroke, a OS 48 Surpass. I need some help on plumbing the fuel lines. (I got this engine from a Widow and it had no instructions). It has 3 fuel line nipples. One at the carb., one on the bottom of the crankcase, and one on the muffler. My tank has 2 connections with an option for a third. I assume that I get tank pressure from the muffler, but I am not sure what the one on the crankcase is for. Also, I plan to run this engine inverted. Are there any other issues with 4 strokes that I need to be aware of such as after run oil, special fuel, needle setting etc. Please advise....Thanks.