Topic: Carb overflow, help me stop it

[piedy gonzales]

Yesterday, sunny warm, spring baby!

So I decided to go for a little ride.
Motor started, but... On of the carbs was dripping.
It was dripping out of the rubber tube (1 of 4) at the bottom of the bike.
I didn't ride the bike for 1 month.
I can open it and take a look what's going on, but before I do so I would like to know what I'm looking for.
So can any body tell me what's going on?


Cheers,
Pieter

[DaveBarbier]

If your bike's been sitting a while the carb bowls were probably empty. It's not uncommon for the floats to stick a little and drain out the overflow. Next time just rap on the bowl with a screw driver handle and it should stop. If it persists then you might have an issue.


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1978 Honda CB550K

[piedy gonzales]

What do you mean with
"Rap on the bowl"

Btw, it keeps on dripping while driving

[calj737]

Take the handle of a screwdriver, and gently tap the bowl and or body of the carb that's leaking. Sounds as though you have some debris that's clogging up the float valve on that carb and thus the fuel is continuing to fill the carb bowl.

[DaveBarbier]

Tap on the carb bowl with something that's hard plastic. The float could be stuck down so it's not closing the needle valve. A few taps should vibrate it enough to get it unstuck. Don't wail on it but it's ok to give it a little light smack.

If that doesn't do it, I would drop the bowl on the #1 and manually (and carefully) lift the float while having the fuel on to see if it's stopping the fuel flow. If not, the needle valve (the thing the float closes when it floats) might have some debris in it.

It could be other things but this seems most likely to me and it also the easiest to test.


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1978 Honda CB550K

[flatlander]

next time, before you don't use the bike for some time (more than 2 weeks?), drain the fuel from the carb bowls.

[flybox1]

next time, before you don't use the bike for some time (more than 2 weeks?), drain the fuel from the carb bowls.

^ this. . . . but you still may need to bang on the carbs with a wood block or rubber mallet to free up the floats from teh down position.
I do it as soon as I open the fuel

If it continues to drip, you have a blockage in the float valve, or a cracked overflow pipe.

[Vinhead1957]

If it continues, try to isolate which carb and drop the bowl to make sure the float isn't stuck.

[Duanob]

Also shut the fuel tap off and on a few times while it's running. If's just crud stuck in the float valve it will sometimes flush it out. It's worked for me more than once.

I also pull the over flow rubbers until it's fixed just so I can see which carb is the culprit.

[flatlander]

you mean close the fuel tap and let the carbs run dry, i.e. until the engine dies? that has worked for me in the past.

[Mooshie]

Also shut the fuel tap off and on a few times while it's running. If's just crud stuck in the float valve it will sometimes flush it out. It's worked for me more than once.

I also pull the over flow rubbers until it's fixed just so I can see which carb is the culprit.

you mean close the fuel tap and let the carbs run dry, i.e. until the engine dies? that has worked for me in the past.

+1 to Duanob.  What I do is when I know I am at my destination I turn the petcock off, park the bike (so it runs for a few minutes) then I turn the bike off. I don't ever let the carbs run dry (that happened once when I ran completely out of gas and boy was that Mr. Toad's wild ride once I got gas back in it )

[Duanob]

you mean close the fuel tap and let the carbs run dry, i.e. until the engine dies? that has worked for me in the past.

No just do it when it starts to leak. I end up doing this on my way to work. I smell gas at a stop light, look down and sure enough a carb is leaking fuel. Turning the tap off and on a couple of times always stops the leak.

Plus 1 to Mooshie, always turn the fuel tap off on these bikes when parked! I've never owned one that didn't leak after a while of sitting especially on the side stand.

[lrutt]

As I don't ride my classics all that much, I use a fuel mix in them that seems to help prevent this. I run 6ozs of syn 2 stroke oil in 5 gallons of non-ethanol gas, along with Stabil in all the old bikes. When done I drain the bowls. Never ever had one stick nor have my petcocks given me any grief. The oil keeps things lubed, doesn't smoke, keeps tanks from rusting. Nothing but good for me for the last 20 years.

[flatlander]

No just do it when it starts to leak. I end up doing this on my way to work. I smell gas at a stop light, look down and sure enough a carb is leaking fuel. Turning the tap off and on a couple of times always stops the leak.

good to know, thanks!