Talking about center stands, I have asked here before what could have caused the metal fatigue of my main stand and maybe, maybe I have found the answer. As on my bike the crankcase breather tube has always been routed to end on the LH side, I don't rule out acid fumes may have weakened the metal. In this video, Gruzzel* demonstrates how to install the carbs again. To my surprise he routes the breather tube to the
RH side. There is even - surprise, surpise - a guide down there.
https://www.youtube.com/watch?v=lkxVVq_o8mY*BTW, there are no better video's than Gruzzel's on dissasembly and assembly of the CB500 carbs. Perfect to watch on a rainy day. It's almost a Zen experience. Highly recommended.