Yeah, it's comon sense, but alot of people don't get it right off. I was ready to give up here, but somewhere along the line, the nipple on the muffler got plugged pretty badly. Todays earlier test doesn't count now. Im puttin the ST back on and trying again with both tubes unplugged first, see what happens, then if needed, re-plug the one. If I still have no luck, then i'll give up on it. Im back to work... lol Isn't this a fun hobby ?