Hi there.
New to this forum. I've got a mates 1943 WM20 in my garage at the moment. I
can start it but it won't keep running and there is a huge amount of wear between the Amal 289 carb body and the slide. I've noticed that these carbs appear to be very expensive on eBay and wondered if anybody can recommend an alternative? I'm prepared to completely disregard originality for the sake of a simple, reliable carb whilst I decide what to do with the 289.
Thanks,

Brooky.

email (option): chasgbrook@hotmail.com

Hi There...If you have a 289 you have the wrong carb for the M20 ..it should have a 1" choke 276. Regarding alternatives, the cheapest option is a new Amal concentic Mk1...You should get one of the Wassell versions of this carb for approx. £75..You will need to set up the concentric to the same jet sizes etc. as an Amal Monobloc, which was fitted to the M20/21 from 54 onwards....Ian.

email (option): ian@wright52.plus.com

hi Brooky,i asked at the Amal counter at Stafford in October,price for a new
276 £225.00,ready to rock n roll,they and i will have to wait
cheers rick

email (option): richardholt@rocketmail.com

Hi Brooky,

Check out this thread...

http://pub37.bravenet.com/forum/static/show.php?usernum=3155626639&frmid=16&msgid=1111071&cmd=show

Regards,

Hank

This may be sacrilege to some, but I successfully fitted a Mikuni to an AJS several years ago. Someone else I know replaced a pair of a Dellorto with a pair of Mikuni. They are good quality, inexpensive and as they say in Afrikaans (an old Dutch dialect), they are a “kan nie dood nie”.

email (option): pvlietstra@gmail.com

Hmmm! Google translate says "Can Not Dead" Ron

email (option): ronpier@talk21.com

If you go down the concentric route you will need that bloody great spacer BSA fitted when they went to the monobloc.
Cheers, Mick.

email (option): mick@motorbikemike.org.uk

Unkillable or immortal..?

email (option): wariron@tpg.com.au

Thanks everybody for your replies. I'm looking at an Amal 932 at the moment.
Is this likely to be suitable, with enough heatshield spacers? I have no
idea as to what the various model numbers of Amal carbs mean. For instance, is the 932 a 9 series 32mm carb or is there no significance at all to the model numbering?

Brooky.

email (option): chasgbrook@hotmail.com

Hi Brooky...You more or less guessed correctly on the 932.(it's a 900 series carb 32mm choke size)..However, a 26mm carb would be more appropriate for an M20...Ian

email (option): ian@wright52.plus.com

A 932 carb I believe would be far to big for a wm20, As Ian said a 26mm carb would be more like what you need.

OK. Point taken. How about one of these;

http://www.ebay.co.uk/itm/300815391536?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

It's apparently off a Bantam but appears to be a 626. Can it be that a 175 Bantam and a 500 M20 could share the same size carb? If it is suitable, I imagine it will need re-jetting. There's also this one;

http://www.ebay.co.uk/itm/180989574747?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

This is the Wassell version of a 626. What do you think?

Brooky.

email (option): chasgbrook@hotmail.com

Hi Brooky...I've fitted a few of the Wassells 'Amal' carbs and they seem to work well.
Personally I would buy one of those jetted for an M20. You are taking quite a gamble with anything second hand and I think the two stroke versions are slightly different anyway... At £80 it's cheap for a new carburettor as well!....Ian

email (option): ian@wright52.plus.com

A carb for a bantam,I believe is a 2 stroke one,If you have the money I would get the 276 amal jetted to suit the m20,if not then the amal 626 4/stroke one but the jetting will be different.I have had not much luck with Wassel products,saying that their carb`s may be ok? I guess after a couple of bad experiences I will not be rushing out to buy any more.

Brooky,

There's an outfit here in California that will make your AMAL pre-monobloc good as new. For the pre-monobloc they will make you a new stainless slide then bore the body to fit the new slide. I had them do this on an AMAL 276 for my '37 Norton Model 50. I couldn't be happier, and works as well as the one on my WM-20. Their work is first rate, the new slide is a piece of art, and the carb works faultlessly. I'd say pick up a decent 276 and send it off to them.

They can be found here: http://www.amalsleeve.com/page2.html

Best of luck,

Mark

email (option): wingco40@hotmail.com

When the 276 died the morning of an important club ride ( Trev's mystery tour ) I whipped the 932 off the ( terminally ill ) B 50 and whacked it straight on the WM20. The logic of this was it was already jetted for a 500 so there was no change of running lean & killing the M 20.

Well it ran like a rocket ( III) with the 932 on ; drank more fuel than a A 75 , refused to idle and had no bottom end pick up at all ( needed to slip the clutch to start off ).
I got a it over 20 mph better in top gear on the flat but no power at all and oft had to go back 2 gears on long hills.
I persisted with it for a year or so, swapping jets & slides but eventually gave up and took the 626 off the B40 ( 350cc ).
From the start it was much better, idleing was problematic, but it could be done, the tree pulling out bottom end torque was now about up to a big shrub and I was only down 10 mph in top from the 932 but could handle hills in 4th or 3rd that with the 932 on I had to go back to 2nd to climb.

It took me about 3 years of fiddleing about to finally get the carby running right.
I still need to "tweak" the throttle stop every now & then to maintain a reliable ( if a bit fast ) idle, but I am really happy with it.
So naturally the gear box has now packed it in

email (option): wariron@tpg.com.au

Hi Trevor,

That sounds encouraging. The advert selling the Wassell 626 says that they will jet it according to my requirements but I've no idea what my requirements are. What jets/needle settings did you settle on for yours?
I think I'm getting somewhere now!

Brooky.

email (option): chasgbrook@hotmail.com

Hi Brooky...Ask them to install the same jetting/slide cutaway etc. as an M20 would have if it were using an Amal Monobloc type carb..They are offering the jetting service so I guess they hold all the required information...Ian

email (option): ian@wright52.plus.com

Had a few minutes to spare so I thought that I would have a look at the jetting for you.
Well ,, errr ,,, umm guess what ?

At some time I have swapped the 626 for a 928.
Don't remember doing it but then again I don't remember doing a lot of things.
Now for what it's worth, this is what I am running at the moment and it works really well.
928 Concentric
No 3 slide
106 needle & jet
220 main
24 pilot ( old body with replaceable pilot )
Off set inset A65F pill box filter . ( think the spitfire ones are the same )

Bike Beesa
Trevor

email (option): wariron@tpg.com.au

Thanks Trevor. That will be very useful if I go the concentric route. I'm currently watching a 276C/1B on fleabay and will probably have a go at getting it. Hope I'm not going to be fighting anybody on here for it!

Brooky.

email (option): chasgbrook@hotmail.com

Hi Brooky,

I have a 276 that came off my M20. I replaced with a new amal 276 and now the old one is sitting there. It probably still needs to be rebuilt but everything is there if that helps.

email (option): jeff@infinitymedspa.com

Hi Jeff.

That's very tempting. The 289 on the bike at the moment is totally worn out, in that there is a huge amount of wear between the body and the slide so the engine is drawing a lot of secondary air and I simply cannot get it to idle, however fast! Has your old 276 got similar wear or would you say it was acceptable and do you know of anybody that can refurbish a 276?

Brooky.

email (option): chasgbrook@hotmail.com

I think it is acceptable but I ma not an expert. I have always felt that carbs are finicky in the first place, so anytime I have tried to make something work in that area it costs me more time than it is worth. That is why a bought a new one. If you took mine I would rebuild it with seals and a slide. I believe you can get it from amal.

email (option): jeff@infinitymedspa.com

When I was restoring my wm20 the 276 carb was leaking fuel everywhere so before I tried to start the bike for the first time I pulled the carb apart and used wet& dry and a piece of thick glass to reface all the joints I could.I replaced the float needle [used tooth paste to seat] and all jets plus gaskets,The bike runs great, it never misses a beat and never had to change a plug,alot more than I can say for other bike`s I`ve had when I fitted different carb`s on,hours,day`s,week`s,month`s getting them to run right.So now if at all possible I try to keep the same type of carb on the bike as it came from the factory.By the way after rebuilding bike,motor, gearbox etc [basket case] the wm20 started on the first kick,I nearly died of shock

Hi Jeff (Robbins). I've emailed you.

email (option): chasgbrook@hotmail.com

Hello, hello! Calling Jeff Robbins. I'm interested in your old carburettor. I've sent you an email. Could you get in touch please? Thank you very much.

All the best,

Brooky.

email (option): chasgbrook@hotmail.com