Here's the skinny. I rebuilt the top end of the bike. I never took the exhaust valve apart, just cleaned it up as best i could. It operated fine when i moved the arm back and forth on the side of the cylinder. Here is where I think I screwed up. I put the cylinder back on bike and checked the valve again to make sure it acuated and it did, it opened and closed just like it should. The only thing is that the valve is in the up/open position instead of hanging down like I think it should be. I started the bike with the cover off to see if it went in the down position while running and it did not move. I guess the question is, is there any way to fix this without pulling the jug, and making sure that the valve is in the down or closed postition before sliding it back on the bike where it meets the thing coming out of the case. I have no low end whatsoever and I kept thinking it was jetting, but this sounds like my problem since the bike ran fine before. Any input would be greatly appreciated. Thanks