Carburettor leaking fuel

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PaulWoolley
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Carburettor leaking fuel

Post by PaulWoolley »

Good evening
I have used an Amal refurb kit on my Ariel leader carburettor and it leaks fuel from most orifices,
Can anyone advise me how to solve this tricky problem please.
Cheers paul
JohnnyBeckett
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Re: Carburettor leaking fuel

Post by JohnnyBeckett »

hi paul, it can be the float valve not shutting the fuel off or the float level is too high
Simon.Gardiner
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Re: Carburettor leaking fuel

Post by Simon.Gardiner »

I replaced the old float and needle in my 375 with new 'ethanol proof' versions from Amal and also added the fibre washer under the needle valve housing as is often advised when fitting the 'ethanol proof' components.

However, I found that with the fibre washer the new float and needle arrangement was rising so far that the float hit the tickler before it shut off the needle valve (ie fuel everywhere just as if the tickler was being held down.)

Longish story short, discussion with Amal pointed me to the shim packs they now provide to go under the needle valve housing so you can adjust the fuel level without using the too-thick fibre washer. (These only show under 376 although they're for the 375 as well so I hadn't found them.)
https://amalcarb.co.uk/monobloc-series/ ... ttors.html

HTH

SG
Web admin (webmaster@arielownersmcc.com)

'55 Huntmaster, '56 VH, ' 51 VH, '62 Arrow, '80 R100RT, '00 Sprint ST (now with a new Arrow project, and just now those 4-stroke Ariel parts can't even make one running bike...)
PaulWoolley
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Re: Carburettor leaking fuel

Post by PaulWoolley »

Hi both
Thanks for that, I have used the ethanol proof valve and will get the shim pack asap and give it a go
Cheers
ian williams
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Re: Carburettor leaking fuel

Post by ian williams »

i lowered the float level on my amal 375 in my 58 leader as i noticed the level was right up at a point it could easily flood the engine .
what i did was to turn down the float needle valve union face and check the level of float as i went , i have dropped the float by 1/4" down from an initial mark i made before i touched things .
you can turn down the face down of the union more than needed and then fit a fibre washer to lift float up but if you have different thickness washers can set the float to desired level , or could use the shim kit from amal .
i found that with original carb i could lift float but not drop it because there is no shim or fibre washer used on the original carb and float valve union .

i know with the concentric carbs you can simply alter height of float by altering the level of the pressed in bushing but with the monbloc it seems you could only go one way and not the other lol .
regards
ian
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Re: Carburettor leaking fuel

Post by Ivor Collins »

Hi Paul
I assume you know that the ‘pip’ protruding from the float bowl cover is the correct fuel level and you should be adjusting to suit?
PaulWoolley
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Re: Carburettor leaking fuel

Post by PaulWoolley »

Hi Ivor
Thanks for that, I will give all the welcome advice a go next week
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Re: Carburettor leaking fuel

Post by Ivor Collins »

Ah, so what you need to do is fit a clear plastic tube to the projecting pilot jet after removal of the pilot jet cover nut. The height of fuel in the tube should be seen to match with the pip on the cover.
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Re: Carburettor leaking fuel

Post by PaulWoolley »

Fantastic, thanks now I've got it
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