Hey all,
I just wanted to post some advice when diagnosing a running problem. We all know that these B400s suffer from frequent carb issues, but I had another underlying issue keeping me from solving my carb issues last summer. Check your Cam Timing!!!!! My bike had jumped time (not like Michael J Fox) and as such ran like sh*t. Additionally, two of my exhaust valves were very tight. So, I know its not a fun job but, pull the valve cover and check valves and cam timing before you go nuts pulling the carbs apart 300 times. With my my #2 b400, I know the problem is the float needles partly because I have checked the timing and valves already.
Mac