Occasional carby leak

Hey guys ,I seem to have an unusual problem with my carby , I'll star by saying pin and jet clean as a whistle , carby float in great condition , brass tang is in great condition and pin on it is fitted correctly but despite this.......

I keep on occasionally getting major leaks from the carby , for example I took my build to the shops ,no leaks prior to trip , pull up at the shop ,lock her up and get the shopping , come out to the smell of 2stroke , look at belle and she has a pool of fuel underneath her , I tap the carby and she is dripping very badly , she starts and runs well with slight 4stroking when taking off ( I believe from an excess of fuel in the system) ,after this burns off she runs beautiful ,I get home check for the leak and it's gone , which sux coz I can't diagnose the problem when she isn't leaking , it's happened 4or 5 times now and it's driving me nuts

Any ideas as to what the problem is and how I can stop it ,oh I have already bent the tang arms down to slightly lower the fuel level in the carby

Regards Henshooter

2door said:

Hen,
Are you using an in-line fuel filter? This sounds like crud getting caught in the float valve. The kit tanks are notorious for having rust, dirt and scale in them. They need to be cleaned and flushed before installation and then a good in-line filter installed between the tank and carburetor.

Also it is always a good idea to shut off the fuel petcock when the bike is parked. Even with a properly working float valve fuel can seep, especially if the petcock doesn't shut off completely, and give you the condition you describe.
Check the petcock to see if it completely closes in the off position.

Tom

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Thanks Tom ,I've checked the tang and action it seems fine ,also I've always run a good inline filter , yes admittedly I've occasionally left the fuel valve in the on position ,lesson learned I guess ,it is one of those mulder and scully mysteries I guess

It just baffles me as to why it only occasionally does it ,apart from this issue she runs sweet and doesn't miss a beat anymore

Cheers for the advice Tom

Kioshk said:

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HAHA !!! Your a funny bugger Kioshk

Theon said:

How level did you get the carb?
Can you post a pick of the carb and inlet manifold please, I may be able to send a better manifold?

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Carby is as level as I can get her Theon , I just can't put my thumb on this problem , I've checked the interaction between the tang and the valve arm and it all seems to be fine , but the main issue is I can't diagnose the problem because it only ever happens when I'm out and ripping the carby off in the middle of the street when the problem is happening is least from desirable in my neighbourhood .

The inlet manifold I have on this kit is slightly larger than the regular one and uses Allen key bolts to secure to the head ,it's quite small being only about 1 inch or 3cm long ,the mouth of the inlet is also larger than the regular model and the bolts on it are roughly 4 mm further apart from a regular kit , I've got the manifold inlet you sent me but It won't line up at all , I would have to mill the anchor points at least 4 mm either side to allow it to fit and the same goes for the internal diameter of the inlet

Christ my head is spinning

Regards Henshooter