mojoblues wrote:The reason for opening was that the bike would not start, you could hear the chain inside spinning, but it was like it couldn't catch something to start it .
This is a starter clutch issue. Have a look here.
mojoblues wrote: I could start it by pushing, in 2nd gear, but it would run very rough, I was constantly twisting the throttle to keep it running. Mechanic said that it could be the cam chain tensioner.
Sure it could be. Or something else. Maybe it was just runing on two or so.
I love that kind of mechanic.
mojoblues wrote:Also, since it was from the beginning running rough on slower rpm's, I thought it would be good idea to clean the tank and carbs (esp. slow jets).
Very good idea!
No precise idea about that missing part. But it looks like something cracked off by a too long bolt, it does not look like a moving part. Is there a thread inside?
Here is how it should look like at the yellow circle: viewtopic.php?f=4&t=8853&start=25. Guess it is a cast knob or so. So probably nothing missing there.