Ideally I'd like to make the subject CM400A/T/C/E because I believe this applies to all of them (may even be the same part). I finally got everything buttoned up on my CM400A except there is a small air leak from the Air Cut-Off Valve cover. Specifically, it is the o-ring. It's shrunk and flat. I verified the "pumping noise" went away by holding my thumb tightly over the hole with the cover off and the bike running. Otherwise, I get a pumping noise that's an obvious air leak, and at higher speeds (above 30mph) if I let off the throttle you can hear this obnoxious high pitched pumping sound.
I'm sure someone knows the o-ring size, but I am wondering if anyone has used the kit from 4into1? The diaphragm itself on the valve is kind of "eh" so I probably should just replace it now that I've disturbed it.
