Author Topic: Fuel Leak  (Read 379 times)

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13Brads

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Fuel Leak
« on: 11 May, 2020, 16:18:05 »
Hello.
My M21 has developed a fuel leak. 
The petrol tap corks were replaced some time ago but with the fuel lines disconnected from the carb there is a drip from the pipe about once every 5 to 10 minutes, so not a lot. But over night, the carb is wet with petrol so it suggests the float needle/seat is letting by. The float itself is good. So, can the seat in the bottom of the float chamber be removed/replaced? I haven't been able to find this on the exploded diagrams I have seen. Or is it a case of lapping the needle and seat with some metal polish. I should add that this leaking has only just started after some 5 years of ownership.

Thanks

Bess

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Re: Fuel Leak
« Reply #1 on: 11 May, 2020, 19:05:30 »
Hi,
     I'm not familiar with the M21, however I would fit a new Viton tipped needle float:

http://amalcarb.co.uk/carbspec/carburettor/spares/id/6560/

Best wishes...

Dean Southall

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Re: Fuel Leak
« Reply #2 on: 11 May, 2020, 19:30:25 »
I assume you are using a 276. If so I doubt the drip as you describe is due to the float valve unless the fule is comingh from the top of the float chamber. Try nipping up the fuel banjo and or new fibre washers that seal the banjo.
BSA: turning ordinary men into mechanics since 1910

DAVE BRADY

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Re: Fuel Leak
« Reply #3 on: 11 May, 2020, 19:35:29 »
Hi,

Did you just replace the corks or the sliding bit complete with cork?  The corks can wear but they can be tweaked.  Take the sliding bit out of the tap and tap the end retaining the corks a bit further in.  This will compress the cork a bit and make it bulge a bit giving a more snug fit and hopefully stop the drip.

Dave.

13Brads

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Re: Fuel Leak
« Reply #4 on: 11 May, 2020, 21:49:45 »
Thanks Chaps.

Dave. I did just replace the corks. I will try your suggestion to tighten the corks up a bit. However, with the fuel lines disconnected from the carb, I only get an occasional drip from the fuel pipe. I have in the past left the fuel turned on by mistake but the float has always stopped the carb from flooding. So with the fuel turned off and just the aforesaid occasional drip getting to the float chamber, the fact that overnight the carb floods seems to point to the float needle valve.

Dean. It is a 276 carb, and has tight joints with new fibre washers.

Bess. The link you gave me looked promising but is for a 376 carb and I have a 276 fitted as standard with the remote float chamber.

I guess I'd better give Draganfly a ring and see what they suggest.

Bess

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Re: Fuel Leak
« Reply #5 on: 11 May, 2020, 22:25:43 »