Leaking Carb

[Something Odiferous]

1980 750C.  Keihin carbs.  Had the carbs cleaned professionally and he also replaced the accelerator pump.  One carburetor still leaks gas through the overflow.  He told me that it may be a stuck needle valve but I would like some other opinions if anyone has some input.

[cbRider]

It most likely is a stuck float valve.
The reason for a stuck float valve is probably dirt.
Du you have an inline gas filter installed between the tank and the carbs?
If not, I strongly recommend you do it.

To fix the leak with the carbs in place isn't the easiest thing but it can be done.
With a stubby Phillips screw driver remove the float bowl and clean out the float valve.

Good luck.

[Something Odiferous]

This is my winter project bike. (Buy a fixer-upper, fix, sell) There was an inline filter already there and I went ahead and ordered a new one.  I'm going to take off the carbs; there just is not enough room for me to work under there.  I'll look at the float bowls to see how well my cleaner guy did.  Hopefully I can do that without ruining the gasket.  Think it could be the needle valve though?

[holysmokes]

use brasso and a qtip , clean up the needle seats, there is probably crappy varnish in there..also, the needles may be hard and allowing fuel down through..get new needles

[macca k5]

hi i had the same problem took it back to where i bought it and the guy adjusted the level of the float [ with a screwdriver!] boxed it up and touch wood its been pretty well fine since [ although it did play up once and when i pulled the bottom off the carb little bits of black bits came out and once removed all has been good
cheers
Derek

[holysmokes]

it is almost impossible to adjust the level of a plastic float with breaking it, do the q tip method and get some new needles

[Something Odiferous]

I took the carbs off again today.  I probably screwed them up, but I took all of the primary main jet and the primary nozzle, found them all to be cloughed (if that's a word), checked each float to see if they had gunk in them and put it back together.  They all leak now.  I'm taking them to my guy first of the week.  I'm over my head.  Anybody got a good set of carbs for under $200?

[brcree]

I'm having some probs with mine as well....76 750 k6. I have the carbs with the rubber caps on top. Wondering if the float needles are correct. They don't have rubber tips like most do, is this correct?

[Re-run]

In most cases it is a stuck of poorly sealing needle. Try lightly rapping the float bowl with a screwdriver handle and see if it stops. If not, then you will want to drop the bowl and pull the needle and check it out very carefully. Any cuts or scrapes and it should be replaced. Also check the needle seat and make sure it is clean. Most people do not clean those, they concentrate on the fuel passages and jets.

Finally, check the brass overflow tube inside the bowl. It is made to drain the fuel when it gets too high. Sometimes they crack though. If it cracks, you should be able to clean the tube and solder it.