Carb leak

[Adz]

Hello I've just noticed fuel leaking from from my carb (see photo) when I give it a tickle before start up.
Once it was running no fuel was leaking.
Any advice before I start poking around?
Thanks in advance

[groily]

I may be quite wrong, but I reckon that's a very common thing (normal even) with the Type 76 carbs and in my own little world has been the primary reason to go Monobloc if one will go on.
(Makes the need for a drip tray/shield to prevent petrol going down an HT pick-up all the more important too I think.)

[Adz]

Ah right that's interesting. Just weird I've never noticed it before. Seemed like it was quite a of fuel.
Thanks for the reply

[Angus]

Hi ALL my 76/276 Amal carbs do that, even the brand new one on the T100. I spent ages on the Norton one trying to stop it. As you have said it stops when it is running.
My routine now it turn on petrol tickle and start as quickly as possible, when I reach my destination turn petrol off before stopping engine.

[limeyrob]

The tickler holds the float down so the fuel level goes up.  It will raise the level above the float chamber breather so it will pour out.  Once the engine has started it uses up the extra and the float chamber level settles where it should be.

[Adz]

Makes sense. Glad it's normal and nothing to worry about.

I guess I usually tickle and start. But on this occasion I was in conversation and didn't start her up straight away.
Thanks to all that replied.

[Rex]

There is a school of thought that says if you see petrol dripping after tickling then you've tickled too much! You're only supposed to raise the float level for starting not wash the grease stains off the engine..

[Adz]

Haha yeah fair enough.

[Triton Thrasher]

There is a school of thought that says if you see petrol dripping after tickling then you've tickled too much! You're only supposed to raise the float level for starting not wash the grease stains off the engine..

Schools of thought won’t start my bike on a cold morning.

[Swarfcut]

 If my Specsavers are working, that carb is an AU series 276, I suspect it came from a Norton (ES2?) originally. BSA A7 fitment for 1950 A7 is 276 DP, '51-'54 it's 276 EU. The letters and numbers specify the internal components and their factory settings.

 The hole just above the mixing chamber big chrome nut is a vent, this link may help explain the what's and why's of a fuel drip from the carb after an enthusiastic tickle. No drip otherwise? It's fine.

   www.nortonownersclub.org/forum/es2-amal-276au1be-leaks

 Carb drip shield is a must for any magneto bike., 276 carbs were always prone to dripping, so this is par for the course, bikes have been lost through a magneto getting a good dose of fuel. The monobloc design is an improvement, easy fit swap on a Plunger A7 with lower block height, tighter squeeze on the A10.

 Swarfy


 Additional.
     You'll be the envy of  your peers with this must have mass produced high quality drip shield. The must have accessory for keeping your drips shielded in the most arduous operating conditions. Available in a choice of finish, aged patina to a mirror polished sheen.

 Trying my best here at AI, Rob. See next post!!

[limeyrob]

I've got a carb drip shield for sale on e-bay at the moment and no one wants it.  Keep talking them up please

[Rex]

Schools of thought won’t start my bike on a cold morning.

No indeed, but nor will the little puddle of petrol on the floor. A happy medium is called for.

[Triton Thrasher]

Schools of thought won’t start my bike on a cold morning.

No indeed, but nor will the little puddle of petrol on the floor. A happy medium is called for.

The ground isn’t the floor.

[limeyrob]

I'm not happy until I see some petrol come out and drip down. That's my check that the carb strainer is not blocked with rust flakes (again..).  I've wasted too much energy kicking over a bike with an empty carb.

[Triton Thrasher]

I'm not happy until I see some petrol come out and drip down. That's my check that the carb strainer is not blocked with rust flakes (again..).  I've wasted too much energy kicking over a bike with an empty carb.

I removed the tank tap gauzes and fitted a paper element inline petrol filter years ago and have never had a fuel blockage since.


Sadly deceased beasties notwithstanding:



I ripped the gauzes in the carb banjos open as well, but that was probably unnecessary.