Topic: newbie question (Fuel leak)

[birdie]

Hey,

    I've a 73 cb500f and my problem is that i constantly have fuel leaking out of the bottom thru a fuel line (overflow / drain?).  Like my subject heading says "newbie question" so please understand where I'm coming from!!  Thanks for any help.

[Dennis]

Is this with the engine running or after it is shut off and left with the fuel petcock turned on?
Do a search of the website.
Very common problem. And a very common newbie question.
No point in my repeating it all here since I'm a terrible typist and it would take me an hour to type.
I hope that you have either purchased or downloaded a repair manual, you're going to need it!

[SteveD CB500F]

Yep.  You've got float valve problems, probably due to gunk from the tank.
Search on "float valve" etc and read the FAQs about cleaning carbs.

Moved from Non-SOHC (can't have fellow 500Fs in the non SOHC4 now can we ??)

[TwoTired]

Another possibility is that the overflow standpipe in the carb bowl may have a crack in it.
Isolate which carb or carbs that are over flowing.
At the bottom of the bowl facing outward is a drain screw.  Put a shallow catch pan under it and remove the screw.  Examine the drainage.  If you can locate particles bigger than .4mm or .016 inch then you have a fuel contamination problem.  These pieces can plug up jets as well as block the float valve from closing.
  To check for a cracked stand pipe, you'll have to remove the carb bowl.

Prepare to improve your manual dexterity.

Oh yeah, and read the FAQ.

 

[Harry]

Give your carbs a sharp rap with the handle of a heavy screwdriver to see if you can loosen things up in there.

[Finbar20]

What Harry said. My 350f was doing that, Played those bowls like a xylaphone. Narrowed it down to #4. Now I just play that one

[birdie]

Thanks for the replies... i'll let you know what it was after i tinker with it.