Well I am still trying to sort out the carbs on my 71 CB500k. I have had them off to clean and inspect, and after putting everything back together, I am only running on 3 cylinders and two carbs are leaking out the overflow tubes, and it's quite a lot of gas.
So first, the overflow problem: Strangely, this leak seems intermittent. It seems to happen after being parked for a few minutes. It's happening on cylinders 1&2, and cylinder 1 is the one that is not firing. I checked the float heights, all seemed good, and I verified that the floats all operate freely. There was no (visible) gunk behind the needle valve. So, could the needle valves need replacing? I should mention that I patched a couple of the overflow tubes in the carb bowl with JBWeld, though I checked for leaks and found none.
Now the three cylinder issue: Cylinder 1 is not firing. I have verified that cylinder 1 is getting spark. It seems to be an air/fuel problem. I pulled the carbs off again today and found no obvious problems. No gunked up channels that I could see. Could I just be missing a passageway in the carbs somewhere? Is there anything else I can look for? Oh, and I forgot to inspect my manifold rubber before I came in for the night (doh!) but it looks okay on the outside.
The air/fuel/whatever screws on the outside of the carbs were all set out too many turns according to the manual. I "fixed" them, but it made no difference, I still had only three cylinders. So perhaps another thorough cleaning for carb 1? Any other ideas?
I am so thankful for "Motorcycle Classics," my favorite magazine! It just so happens that they are doing carbs in this month's issue on their honda cb500 project! There are great color pics and clear instructions on how to disassemble the carbs. I found it immensely helpful.
Thanks everyone, this site has been great to me!
