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Carb leaking fuel

Featured Replies

Hi all my carb is leaking fuel out of the overflo and sometimes can be a pig to start, especially in gear and sometimes stalls going down hill but this could be me holding it on the brakes.

Cheers

Adam

Adam, float height may be wrong or the fuel inlet needle may be dirty and allowing fuel to flow in the float bowl when its in the closed position. Take the carb apart and clean thoroughly using carb cleaner and an air line if possible. Make sure you blow the jets through in the right direction and hopefully someone here can advise on the correct float height. To much fuel in the bowl will cause stalling whilst going downhill.

check your carb floats don't have any fuel in them, they can crack and let fuel in and then don't float as well

most likely piece of dirt on float valve seat or valve seat has hardened so doesn't seal

fuel overflowing into cylinder would make it a pig to start

good luck

tony

Edited by tonybroad

  • Author

Please refer to pinned topics at the top of this forum for a guide. :thumbup:

Can you point out which thread gives detail on how to fix this as I must be blind but can only find how to do the pipe method no pics showing the other methods

Cheers Adam

  • Author

check your carb floats don't have any fuel in them, they can crack and let fuel in and then don't float as well

most likely piece of dirt on float valve seat or valve seat has hardened so doesn't seal

fuel overflowing into cylinder would make it a pig to start

good luck

tony

Hi Tony

Is there any manual you can buy or video on here showing the mods on the carb or how to take the carb to bits and set it back up

Cheers Adam

  • Author

Cheers for that will have a read tonight, just realised I talked to you today enquiring about the Ryan young DVD, I will phone again at the end of the month

Adam

There you go! I was about to ask for professional Beta help here mysel, as seems the orig Billy T post has gone!

Yeah the Billy T article opened my eyes. Nippering a small hole in each of the vent tubes halfway up the carb body stopped the fuel leak siphon problem on all the bikes I've done it to (~10). Works like a charm, costs $0. The extreme angle the Beta carb sits at helps it run strong on steep ups but requires the float level be correct or slightly low or it will stall on downhills. I've found this to be true on the Mikuni and the Keihin.

Edited by Dan Williams

  • Author

Ignore the drilling.

See diagram here: Beta Carb Mod.

Just alter float arms/tangs, that does it.

I have read this and will have a go next week but just so i no how do you alter the tang and tab as i have never took a carb in bits so dont know what i will be looking at. Is it a case of bending or do you have to screw it out for example

Cheers Adam

Yup bend the tang the needle valve attaches to to set the float level. Bend the little tab that points up at a right angle along the pylon that holds the float pivot to set the float travel. Don't be afraid, it's not as scary as it sounds. It'll be pretty obvious once you pull the float bowl off.

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