Top Feed Amal 47/022/sLAC Float

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135 Z1
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Top Feed Amal 47/022/sLAC Float

Hello Everyone,

After using my new old Dennis Z1 for a while i found that it was revving very high at tickover and that petrol was leaking uncontrollably from the top of the float chamber.

Having disassembled the carb the problem became quite evident. The float in it is not an original manufacturer part but a rather ingenious home made affair constructed of 2 X 1 1/4" copper end caps soldered together with a needle stuck through the middle. The problem was the solder had failed leaving a crack round the centre line so allowing fuel in and turning the float into a sink.

Having filed away much of the original solder to make it a bit lighter I managed to seal the crack using a thin smear of JB Weld 2 pack reinforced epoxy and then to adjust the screw on the side of the carb to archive a really slow and even tickover. Whereas it now seems to operate correctly I would like to obtain a new, or usable second hand, float. Does anyone have such a thing or know where I could obtain one from?

Thank you

Daniel

DJD
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Joined: 06/09/2013 - 14:19
I've got some old floats and

I've got some old floats and will see what I've got for you soon. But " 2 X 1 1/4 end caps" please give dimensions of what you need replacement to be?

135 Z1
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Last seen: 19 hours 32 min ago
Joined: 03/04/2021 - 16:23
Thank you DJD this is a most

Thank you DJD this is a most excellent new,

I have Googled this to pieces and I cannot find the size of the float I require.
I found this on the OLC site which may have given the answer but it is as unintelligible to me with or without my glasses on.

https://www.oldlawnmowerclub.co.uk/sites/default/files/memberuploads/use...

Another alternative source of info may have been the Surrey county archives where they keep some of the original Dennis drawings including one for the Amal 47/022/s unfortunately although the catalogue of drawings is available online here https://www.surreycc.gov.uk/__data/assets/pdf_file/0006/36456/Dennis-Dra... (Page 288 for the carb). The drawing itself is not available online unless I pay to have it digitised.

Having said all this and based on it having a separate or detachable float chamber I think it is what seems to be commonly referred to as a pre-monoblock and I am presuming that the /022 part of the number refers to the contents of the float chamber in which case I believe the float to have the Amal part number of 22/016 and the needle 22/014. If this assumption is correct then it would be the same as the one in Amal Types 46, 223, 523 or 332 some of which are available here

https://www.vintagecarbfloat.com/online-store/search%3Fkeyword%3Damal

and they give the dimensions as being 32mm Diam, 36mm Height and 8-9 grams in weight for the 223,523 with the clip top but without the needle, or dimensions of 32mm Diam, 33.5mm bulb Height and 9 grams Weight for the same with soldered in needle.

It is all as clear as mud, or my garden having run the mower over it.

Tomorrow I will contact vintagecarbfloat and see if they can throw any light on the subject

Thanks again for the offer and I may yet need to take you up on it.

Daniel

 

 

 

DJD
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Last seen: 6 hours 33 min ago
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"Having said all this and

"Having said all this and based on it having a separate or detachable float chamber I t"

Do you have the remote float chamber or not? If you do then it's a fairly simple matter to to deduce the diameter of the correct float for starters, correct float will be a loose sliding fit, as a general rule,  the fuel inlet needle is another big clue because it needs to sit in the bottom end of ally casting and top working end ought to be long enough then to be captured by the top cover.

I bought a truck load of old motorbike stuff along with Amal pre monobloc and other similar carbs, 99% of which went very cheaply on ebay years ago, I still have a few odds and ends knocking about, but I will see what I have now I've got a basic idea.

If you don't have the remote float chamber then I can't see how the carb would actually work without? I'm a tad confused here.

135 Z1
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Last seen: 19 hours 32 min ago
Joined: 03/04/2021 - 16:23
Thank you DJD,

Thank you DJD,

Sorry if I did not make myself clear. I do have a complete carb and, despite the condition of the float, now that I have sealed up the crack and I have something that floats rather than sinks it can be made to work.

My understanding of this kind of carb (and I may be wrong) is that as it all functions by gravity, the only regulation of the pressure of the fuel entering the mixing chamber is by the level of the fuel in the float chamber and so this level is important to correct operation.

I would like to find a replacement float because the one I have is very dented and almost certainly the wrong weight (too heavy with all the added solder and epoxy) and this will lead to the level of petrol in the float chamber being too high and therefore the rate at which it is dispensed into the mixing chamber also being too high so leading to an over rich mixture which I certainly have judging by the black deposits visible around the exhaust outlet.

Daniel

DJD
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Last seen: 6 hours 33 min ago
Joined: 06/09/2013 - 14:19
These are the two I have that

These are the two I have that I think are the closest to what you need. One has the needle soldered in, but has been damaged underneath. The other has a removable needle which is fixed in via two pieces of wire on float top, (more like a typical Villiers type?) the valve part is at the bottom, which engages with the inlet valve on bottom end of carb.

The bottom end inlet valve area.

The second one looks newer, but is damaged.

Top only is generally 'sharpened' on this type to fit a top end shut off valve for fuel.

Bottom end has no need to be sharpened to a point, you can often get a dent out of a float like this via very hot water, not direct heat, which can melt the solder, then you could be in a worse position.

First ones shaft goes almost 2.4 mm.

Thinner one is only 1.9mm.

You can email me if you'd rather, I thought I still had a few remote chambers about unsold, but they are not where I remembered leaving them, I think they came from those, but not 100% sure now.

No need to make any decisions at the moment, see what your other findings throw up firstly and we can decide what's the best for your machine and you.

 

 

135 Z1
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Last seen: 19 hours 32 min ago
Joined: 03/04/2021 - 16:23
Hello DjD,

Hello DjD,

Thank you for your trouble in sorting these out.

In my search I found this Pdf of AMAL Parts for among others the 47/022/s which I share here with everyone as it may help others identify parts.

https://drive.google.com/file/d/1oYJYxnSaT23JISCD_no7vaVbJum7amTo/view?u...

From this I now believe I am looking for part number 22/062 (the float)

The one I have measures 31-33mm Dia depending on which dent/lump of filler I measure to and would once have been 32mm in Height.

Looking at the floats you have  the copper one looks to be a good match to mine.

The needle I have is indeed the correct top feed type and I could unsolder and re-use mine.

If you would consider parting with it I would be happy to pay for it and postage

Please feel free to conduct negotiation via E-mail

Daniel