Topic: Cb500 carbs leaking badly

[vonvendetta]

So I went for a run the other day and noticed the bike was starting to shift a little rough after 30 minutes on the road, mild slipping. Pulled over and noticed gas just flowing out of the overflow. I've set them to 22mm and replaced the springs to the float bowls. What else should I check for?

[Gene]

I'm going through this on a 550.  Check 2 things: Your float valves (also make sure that 22mm was correct - ONLY touching the spring, don't measure it if they're upside down) may be rounded or pitted or some piece of gunk is keeping them from closing.  Also check that your overflow piping doesn't have a fracture.  I've seen some posts where there is a hairline break in the brass tube itself causing the leak.  If you're not flooding out this might be the case.

[DanEarl]

+1 on the overflow tubes being cracked. I had this happen on my bike. Trace the leaking overflow hose up to the carbs to see which one is leaking. I just replaced the float bowl with one from a spare rack of carbs. I saw on this forum someone fixed the tube with some electric shrink wrap.  Assuming that stuff holds up being soaked in gas all the time, pretty neat fix!

[volare71]

New float valves, check the overflow tubes, and new bowl gaskets and you ought ot be in business.  You don't need to remove the carb assembly for these fixes.