This is a reproduction of the original 180 Degree banjo that was fitted to Amal TT, RN and GP alloy froat chambers from the late 1930's onwards.  This 180 Degree type was most commonly fitted to Norton SOHC (and Manx Norton) carburettors - and is much rarer to find than the '90 degree' type more commonnly fitted to other motorcycle marques using the Amal competition carburettors through to the early 1960s.  

Price is per each banjo, but includes the two red fibre washers fitted either side of these banjos - from a high quality manufacturer.

This type of competition banjo were fitted to the Amal TT, RN and GP carburettor float chambers that were used from the late 1930's onwards.  I expect most customers looking at this listing will be familiar with their own carburettor - but please note that earlier pre-War TT carbs were often fitted with a brass floatchamber, which used a smaller bore banjo - if you have that earlier type of float chamber - then sorry, this banjo will not fit.  Email us for details and dimensions on sales@racingvincent.co.uk if you are not sure and want to check.

This style of alloy cast banjo were originally produced in twin inlet 180 degree type (most often used on genuine SOHC Norton machines), 90 degree twin outlet (commonly used on many marques through the late 1950s), and also in single inlet guise - commonly used on the main carburettor body, when using a remote float chamber.  

This 'twin inlet' 180 degree type is possibly the hardest to find today, and although it can be fitted to any marqure using the floatchamber shown in the photo, and the larger/later type 302 Floatchamber . . . it was specifically the type most normally fitted to competition Norton carbs from the late 1930's through to the mid 1950's.

These banjos are cast in heat treated aluminium, using an original 180 degree period casting as a pattern (taken from an original Amal RN Manx Norton carburettor), and then CNC machined to the original bore dimensions and 1/4" BSP pipe fittings.  Each banjo is supplied with two high quality red fibre wahers of the correct diameter for these banjos.

Please note:  The original Amal banjo shown in the photo was itself not of the highest quality - in that the casting lines were quite visible and had been linished as part of the original manufacturing process.  Added to this, the original casting was machined fractionally off centre.  We had these castings cast from a silicone pattern taken from this original banjo (rather than a purpose manufactured 'boxed pattern', which would have been prohibitively expensive).  Therefore, I would be truthful enough to say that the quality of these castings are not of the highest quality, and although each casting has been linished (as the original was) before machining - their finish is not quite as good as we would have liked, and some may be machined slightly off centre as well - as per the photograph.  However, rest assured - each banjo is checked after machining to ensure the full width of fibre washer makes contact ... . and as most are aware, this is now a very difficult item to find - we only have very limited numbers of them (and we have barely covered our manufacturing and CNC setup costs!)

This is the Banjo Nut as fitted to original TT, RN and GP competition carburettors that were fitted with the large banjo type floatchamber - either bottom feed alloy type or top feed Type 302 floatchambers.

These banjo nuts have include the all important lockwire hole and are nicely finished in satin nickel plate.  Price is each.

Most Manx Nortons and postwar International Norton's were fitted with the larger banjo floatchambers that required this type of nut. 

If you have a Type 302 'Remote' mounted floatchamber, whe also sell the banjo nut that allows for the remote mounting - see Item 0292.

We also sell a high quality red fibre washer to fit these banjo nuts (two normally required - one above and one below the banjo) - which is item 0165

This is the topfeed banjo used on Amal Type 302 floatchambers (used from the late 1940's), that allows the float chamber to be remote mounted (i.e. to the top frame rail or similar).

This item is drilled and tapped in its centre which provides the means to remote mount them. As with our other banjo nuts, they are patterned on the original design in brass, then satin nickel plated and are very nice quality, UK manufactured.

Price is Each

We also sell a high quality red fibre washer to fit these banjo nuts (two normally required - one above and one below the banjo) - which is item 0165

This is the red fibre washer that fits between the main Jet Holder and the float chamber (two being used at this point) on original Amal TT, RN and GP competition carburettors.

The same washer is also used on the main banjo's used from 1940's onwards and fitted to TT's, RN's and GP's as well as Remote float chambers (again 2 fitted per banjo fitting. 

These washers come  from a a high quality washer manufacturer and are of a higher quality than any other red fibre washer we have found - they cost much more than other manufacturers (approxiimately 3 times as much as others we have found of similar dimensions), but as the old saying goes - 'you get what you pay for!' . . . I use them on all my own Amal comp carb rebuilds,  

Slightly cheaper than Item 0165 when bought as a pack of six.

This is the red fibre washer that fits between the main Jet Holder and the float chamber (two being used at this point). The same washer is also used on the main banjo's used from 1940's onwards and fitted to TT's, RN's and GP's as well as Remote float chambers (again 2 fitted per banjo fitting.

We get these washers from a a high quality washer manufacturer specifically for this purpose and are very durable - hence the higher price than those sold in the complete washer sets (Item0164). I always use these washer myself when restoring a carburettor - and they have nice crisp edges that also look correct.

Price is per pair of washers

High quality Throttle Slides to fit original Amal 10TT Carburettors in a selection of cutaways - both LH (normal) and RH Sided types available.  Manufactured to a high standard in UK - see below for manufacturing details and more information on the difference between a LH (normal) and RH sided carb.

Price is Each.

Norton SOHC Original Amal TT Fitment by year:

For those fitting a new slide to their original Amal TT carb on a SOHC Norton International - here are the more common original slide cutaways for those models:

- 500cc Mod 30 Norton International 1932 - 1934, Amal T10TT32/34 carb with:  No4 Slide Cutaway ('LH' sided)

- 500cc Mod 30 Norton International 1935 - 1937, Amal T10TT34 carb with:  No5 Slide Cutaway ('LH' sided)

- 500cc Mod 30 Norton International 1938 - 1955, Amal 10TT36/38 orT10TT carb with:  No7 Slide Cutaway ('LH' sided) - the most normal fitting

- 350cc Mod 40 Norton International 1936 - 1937, Amal T10TT34 carb with:  No4 Slide Cutaway ('LH' sided)

- 350cc Mod 40 Norton International 1938 - 1955, Amal 10TT36/38 orT10TT carb with:  No6 Slide Cutaway ('LH' sided) - the most normal 350cc fitting

- 350cc models before 1936 were originally fitted with the smaller Amal 15TT type carbs, which had a smaller throttle slide diameter - sorry we do not manufacture these, but it is not unusual to find them fitted with a later 10TT carb, in which case see info above

- 350cc and 500c Magnesium crankcase (M30/M40/Manx) models from @1937 -1953 were normally fitted with Amal Remote Needle carbs, which used a different throttle slide type.  We also offer these - See Item 0961. 

 It should be noted - for all above, lots of factors including overall carb condition can influence caburation on original TT carburettors.  Therefore these cutaways should be considered a reasonable starting point.  From my own persepective when tuning in the past - I have kept a couple of spare slides of different cutaways . . . so that I can try changing them when setting a carb/engine up for the first time to find the best permutation.  As a general rule of thumb - a No7 slide is considered the best starting point for a 500cc Inter engine and a No6 for a 350cc engine (when fitted with a 10TT carb)

Background on 'Sided' TT slides: if your Amal TT carburettor is the more 'usual' type (i.e. as fitted to all Norton SOHC models) then the air choke casting will be on the right side of the carb body (i.e. visible from the Timing side of the bike) - this type has a 'LH' sided throttle slide fitted (this may sound counter-intuitive, but the LH refers to the side the 'notch' on the slide is positioned, in relation to the cutaway).

We offer this LH (normal) type slide in the following Cutaway Numbers:  No4, No5, No6 and No7.

We also offer the less common 'RH' slide (i.e. the TT carb body will have the air choke slide casting on the left side) in the following Cutaway Numbers:  No5 and No7 

This less common RH slide type original Amal carb was often fitted where twin TT carbs were fitted, or if the inlet tract was pointing more towards the left/drive side of the engine.

We can supply specific information on which throttle slides were fitted to which Norton SOHC models by year and model type on request - email sales@racingvincent.co.uk.  We can also provide details on some other makes on request

Manufacturing Background for these slides:

These slides are manufactured in the UK to a high standard of accuracy and finish - and the manufacturing process has been well proven over a period of many years.  A special (and expensive) grade of Riveting/Naval brass is used for the slide wall- which does not split when the 'notch' is pressed into them.  The slide wall and the top piece are CNC machined seperately to a close tolerance, then the two pieces are silver soldered together on a jig, before going back for final CNC machining and milling.

Finally, the fully machined slides go for grinding - to ensure the walls are true to a close tolerance (this process may be considered unnecessary with modern CNC machining - but is an additional quality factor for these slides).  As a last step - the brass slides are given a very thin coat of nickel plating (only a few microns thick), which like the original period slides - was just to stop the brass walls from oxidising (and note, although the slides look shiny - this is nickel plating, which dulls off with time, as per the original period Amal slides.  However, in the modern world - the original 'dull nickel' plating is no longer easily available, we are told it is now considered eco-unfriendly!).   

Before packing, each batch of slides have their ground outer diameters checked (and we always test one slide of the batch after grinding in an original Amal brass bodied 10TT/RN body with no wear, to ensure each slide has full and smooth movelment, which we keep for this purpose). Finally - we also test each slide for inside fit on an original Amal TT/RN choke block (see photograph) - to ensure it fully bottoms correctly, and slides cleanly, before final cleaning and packing.  Slides are supplied in their own stout cardboard box, to protect them in storage and when posted.  

Remote Needle Throttle Slide Variants:

Finally - if you have an original Amal RN (Remote Needle) carburettor, as originally fitted to most pre-Featherbed M30/M40 and Manx models - we are now able to offer the distinctive 'remote needle' needle type throttle valve for these as well - see Item 0962 in this section of the RN Parts section

Update November 2021: Despite recent massive cost increases for brass/non-ferrous material (i.e. post Covid) and manufacturing costs - we have tried to keep pricing of the latest batch of slides close to the previous pre-Covid price 3 years ago (and price shown is the price you pay, no further tax to pay) - and all slide variants are now back in stock

'Remote Needle' type throttle slide and needle holder to fit original Amal 10RN (Remote Needle) type racing carburetter - these been original fitment on most 1937 onwards SOHC (and pre-1953 DOHC)  M30/M40 and Manx models.  Amal RN carbs were also fitted to many other period competition and 'Grand Prix' spec motorcycles - i.e. KTT Velo's and similar.

For Norton Single M30, M40 and Manx Models, the following slide fittings were most normal:

- 500cc Manx and M30 Models: No6 RN Slide (LH type - whcih these are) 

- 350cc Manx and M40 Models: No5 RN Slide (LH type - whcih these are) 

Background and Manufacturing Information:

As can be seen from the photograph's - these slides are actually based on the similar Amal TT slide design, but the slides for Amal RN carb has an additional threaded hole and slight countersink, to hold a special milled brass sidebar, which holds the throttle needle in a seperate chamber alongside the main carb body - which helps reduce the obstruction of air into the engine.

We have the main slides made to the same specification as our TT slides (see Item 0143), but for these we have the addition of a threaded hole in the top face of the slide.  We also have the special RN throttle needle holder manufactured identical to the original design - and original Amal RN needle holder being used as the pattern - these are CNC milled from billet Brass.

Original Amal RN slides used a flush fitting brass screw to fix the throttle needle holder to the slide - but they also had the threaded shaft of the screw 'mushroomed' underneath, and the holder soldered to the slide - once fitted.  Both of these features were to ensure the throttle needle holder did not vibrate loose in service.  As you can see from the accompanying photos - we have made jigs that allow both of these steps to be carried out - and once completed each slide is test fitted on both an original Amal RN inner block and a virtually new (old stock) brass bodied RN Carb body - to ensure smooth operation.

Note: that as part of this necessary manufacturing process - because we have the TT and RN slides 'flash plated' (to stop corrosion of the slide) first - we carefully remove the nickel plating in the area on top of the throttle slide, where the needle holder is to be fixed - to ensure the best possible contact for the solder.  This is purely cosmetic - and necessary to ensure proper solder flow.   

Stocks of this type of slide are limited, so if you need one, we can only advise you order one quite soon . . . as once this batch have gone, it will be at least 12 - 18 months until we makle a further batch - as you can see from the accompanyning photographs - on top of the normal 'TT Slide' manufacturing processes - there are a number of other processes required - speciific to the original Amal RN slide design - which we follow as faithfully as possible.  

Amal RN (and slide/needle design) Background Information:

As far as I am aware the Amal RN carburettor was introduced in the mid/late 1930's purely for competition motorcycles - in an effort to give a less obstructed airflow through the inlet tract - not unlike the Amal Type 27 needless dirt track carburettor (which I used to have fitted to my old Rotrax JAP speedway bike - and was good for full bore, but not much good for any kind of cutover or slow running).  To do this it moved the needle position from in the centre of the main choke area/inlet tract to the side of the carb.  From what I can gather, it had a reputation for being a better carburettor on long GP circuits such as the Isle of Man or Spa (etc), but was a bit more 'fussy' for slow or mid range running on roadgoing sports bikes, which were normally fitted with Amal TT carbs.

What I do remember as a teenager in the 1970's and 1980's - just starting vintage racing at the time, was that the RN carburettor was not considered as desirable as the TT carburettor for fitting to historic race bikes for VMCC (short circuit) racing, as they were considered less flexible - but really I am not sure if this was true or not.  What was probably far more true was that as the slide got worn and let air bypass - it was less easy to find a replacement slide, so more of them were worn.  I think because of this they were often overlooked. .  . and probably many of them thrown away - making them far less common and hard to find today!

I only remember fitting an Amal RN to one of my Norton's once, and that was back to back with a similar bore/condition Amal TT - both setup for methanol.  If I remember correctly - I could not tell any discernable difference between the two.

Those originally fitted to M30/M40 and early Manx Norton models were of the 'Long Neck' variety (as in the accompanyning photograph - note the inlet tract mounting flange extends past the lower slow running adjuster by approximately 1 inch, while 'normal neck' type carbs have the flange abutting this carb and are shorter.  Therefore, this 'Long Neck' variety are (not suprisingly) considered the most desirable and difficult to find.  However, it is possible to fit short neck type - but it is normal to fit a 1" alloy spacer to restore the full Norton inlet tract length.

Please note if you have a worn RN slide and are intending to try and remove the special throttle needle holder, to re-use it on a new TT type slide - the original fitment of this adaptor is not as straight forward as it looks.  Original slides had ths special needle holder lightly soldered to the throttle slide, and the screw riveted underneath . . . trying to remove that part from an original worn slide will normally damage both the slide and the original slide - we do also sell the throttle needle holder and correct screw seperately - Item No 0962

Correct type conical throttle spring to fit Amal TT. RN and GP type racing Carburettor's

This type of conical spring were fitted to all the Amal racing carburettors - i.e. TT, RN and GP types.  These are manufactured in the UK and are just as per original. The smaller end is placed on the throttle slide and the wider conical end fits at the top stop the spring moving over to one side. 

This is the spring of the correct dimensions to fit the Amal TT/RN/GP air adjuster assembly.  However, It is also of the type shown fitted to earlier Amal TT and RN carburettors, before the introduction of conical springs on competition carburettors. 

These are high quality UK manufactured (plated) springs, of similar strength to originals.  We use them in our Air Adjuster kits.

Price is Each

Earlier TT and RN Carburettor Background:

As well as being of the type fitted to the competition air assembly - this type of spring were also of the type that were found fitted to Amal TT and RN carburettors before the introduction of the more commonly found conical spring (which we sell - Item 0144).  They fit neatly in the recess at the top of the TT/RN carb top, where the original type cable adjuster fitted - this being a slightly larger hole than later TT/RN/GP carbs, which had a smaller adjuster and used the later conical spring.

Another give away if you are not sure which type of spring your original TT/RN throttle slide would have been fitted with - the top of the earlier throttle slides also had a small recess in the top of the cable holder area, to fit the spring - and as you can see in the accompanyning photograph - our springs fit exactly in that rececss (the photograph shows an original early RN slide).  Later slides had a slight recess around the top of the slide to fit the later conical spring (and all our replacement TT and RN slides have this recess for the conical spring).

However, it must be noted that although useful to use for this purpose - you must be comfortable yourself that you choose a spring (either conical or straight type like this item) that is of satisfactory strength to ensure the slide will close fully.  Different people have their own preference on throttle spring strength - some people do not like to have to exert a lot of effort to open the throttle - but it is important to adjust any throttle spring to ensure the throttle will close fully if you take your hand off the twistgrip.  In the past I have adjusted the length of the spring a small amount - to ensure that the throttle will easily close fully once I have let go of the twistgrip.

Note, some people prefer the conical throttle spring anyway, and retro fit those to the earlier carbs - personal choice, but always make sure they are fitted correctly and the throttle can close and open fully