Carburetor problem? Maybe???

[Honzilla]

Hi everyone,

I was washing my bike the other day and I noticed what looked a bit like gas seeping from the bottom part of the carburetor on the clutch side of the bike.

Is this a normal thing for a bike with carburetors?

Is this something to be concerned about?

Is there something that I can be doing to cause this issue?  For example, if I don't turn off the fuel line from the tank every time I get off the bike, will that cause this to happen?
I'm only guessing this because this is the carburetor that is closest to the pet-cock.

Thanks for helping me out...

Also, what do you folks feel about fork braces?  I was looking at purchasing something like this, http://www.pashnit.com/product/superbrace/superbrace_honda.html

Do you think this is worth the money, will I notice the differences they claim???

[Luke M]

The float and needle valve regulate how much fuel is kept on the float bowl. If the float height is not set properly, or if the needle valve is old and/or not sealing properly, the fuel will continue to flow into the float bowl. What you are probavly seeing is fuel coming out of the overflow pipe.
Next time you see this happen, take a screwdriver and give the carb bolw a sharp rap on the side. Then monitor the overflow and see if it stops. If it does, then the float retaining pin may be dirty or restricting the float movement. If not, then it's possible the needle valve on that carb (or the valve seat) may be worn.
Either way, it may be time to pull the carb bank and give the innards of the carbs a good cleaning. Search elsewhere on this forum for guides on how best to do this. Parts won't cost that much, and while you have the carbs apart, it wouldn't hurn to replace stuff (rubber parts, gaskets, etc). I'd start with a good thorough cleaning first.

Hope this helps. Keep us updated, and good luck.
Luke M
Via mobile device (boy, are my thumbs tired...)

[wvhardtail]

LukeM hit it on the head. If you aren't running a front fender then a fork brace is a good idea. The front fender acst somewhat like a brace. I have one for sale if you are interested.

[Honzilla]

Are you selling a brace or a front fender?

[Honzilla]

Thanks for all the info Luke, very informative.

However, I'm not sure if this is the situation...  The "leakage" that I see is not happening real time.  Meaning on the bottom half of the clutch side carburetor there is a residue of something that has leaked on to it.  After testing it with the finger smell test, it smells a little like fuel, but not strong.  Seriously, just like a residue.

Is what you said still a possibility???

[LukeM]

Sure.  I'd be leaning (no pun intended) to the stuck float syndrome, since it doesn't happen all the time.

A reminder: you shouldn't have to separate the carbs to work on them.  Splittlng the carbs up is a lot of work, especially to get the carbs sync'd like they should be.  I took mine apart one at a time, cleaned up the jets, needle valve, vacuum parts, and air passages, and working slowly it took me about 1.5 hours to clean all 4.

Just go slow, take pictures with a digital camera if you think it'll help, and you'll be fine.  See what parts you need if any, order them up, and see if things get better.

Luke M

[Honzilla]

Never worked on carbs before.  Little nervous...

[Re-run]

Carbs are no sweat. Just take your time. Get the manual if you have not. Gets parts trays to hold everything and keep the parts from each carb all together.

[wvhardtail]

It is a fork brace. I think there are pictures of it under the parts I have for sell section. It came on my bike but I am not going to use it.

[wvhardtail]

Here is the link to the pictures.

http://honda-cb750-s.456789.n3.nabble.com/Stuff-for-73-CB750-for-sale-td1469795.html#a1469795

[Lucky 1]

If there is evidence of leaking it means it can leak anytime.
Like when it is in your garage near the hot water heater. There goes you house.

When floats leak there is one simple and only solution - PUT IN NEW FLOAT NEEDLES as soon as possible.

That is the best and only solution. It is silly to try to adjust a float for a leaking float valve.
A leaking float is a WARNING !! Fix it or have a fire.  Not kidding.

The rubber cone shaped float needle can get hard and out of shape. Not concentric. Also they can stick and get gummed up and that is all that is keeping it from leaking is the gummy varnish. Because it is out of round or missing a chunk.