This very useful little item is a 'Top Hat' Ferrule - is to fit original Doherty and other similar throttle twistgrips, which are not threaded at their cable end - and if you are using a throttle cable which has its threaded adjuster in the middle of the cable, not on the twistgrip end - therefore this 'Top Hat' ferrule will stop the cable sliding through the twistgrip hole. 

Background to this item:

We offer both original Doherty throttle twistgrips (Item 0942) and a cheaper offshore version.  Many people (myself included) still like to fit an original branded product if available - for originality sake.  However - the Doherty type twistgrip does not have a threaded end and adjuster fitted - instead it relies on two types of throttle cable fitting:

- A throttle cable that has the adjuster at the throttle twistgrip end, and a nut on the adjuster - then when the cable is fitted, it is the nut that stops the cable from dropping through the twistgrip cable hole

- OR:  if you have a throttle cable with the adjuster mid-cable  . . . and the end of the outer throttle cable is just the normal cable ferrule (normally 0.220"/5.5mm diameter or thereabouts on most old British Bike throttle cables) - then it would normally be necessary to fit a 'Top Hat' ferrule, which slips over the end of the inner cable before fitting it to the twistgrip - and that slides into the end of the Twistgrip, holding the cable outer captive, stopping it from sliding through.

This style of Top Hat used to be available many years ago - I remember seeing them myself at autojumbles and used to have a couple in my cable tin . . . but when a customer pointed this out to me some months ago (when purchasing a Doherty twistgrip) - I could no longer find a manufacturer or supplier of them.

So - we have now manufactured this useful little ferrule ourselves  - they are CNC manufactured from stainless steel - and are also mill/slotted, so they can be slid over the inner cable, without having to remove the bullet at the end of the cable.

Note:  These only need to be used if your throttle twistgrip does not have a threaded adjuster already fitted (i.e - our similar offshore twistgrips are threaded and do have an adjuster

The dimensions are as follows (in case fitting to an original twistgrip or other type of twistgrip or similar):

- Diameter of Top Hat - where it slides into Twistgrip hole: 0.306"/7.8mm

-  Receptor hole for receiving throttle cable ferrule: 0.223"/5.7mm

- Slot width, for sliding throttle cable 'inner' wire through: 0.081"/2.00mm

Please satisfy yourself this is satisfactory for your purposes - and follow all normal safety practices when fitting throttle cables

CNC manufactured by us in stainless steel.  Price is each

Sorry not cheap - a suprising amount of machining (including milling) to make this tiny item!  However we discount this item to £4 if bought at the same time as a Doherty twistgrip from us (Item 0942)

This listing is for the distiinctive shouldered and profiled hex head bolt that fitted to the Inlet ring on Amal Type 76/276 and Type 86/286 Stub Fitting Carburettors - it having the important function of ensuring the carb was securly located to the inlet stub.  These are CNC manufactured by us to the original design in stainless steel and the heads lightly polished.

They were also used on Competition TT/RN clip fitting carburettors.

Price is each.

We have replicated the original design of this small bolt - which as you can see in the photos - has a distinctive grooved shoulder - so that the actual hex of the bolt is held out from the inlet clip - to allow for the best possible tightening with a ring spanner.  This small detail may seem incongrous - but when you realise that it is this bolt that correctly tightens the whole carburettor to the inlet stub - and that on many motorcycles, the head of this bolt was not easy to get good spanner access to - it makes you realise how important a job it has to do!

Because of this difficutl access, and because of the engine vibration and weight of the carb - it is not uncommon to find that the ''Stub' fitting type carburettors often have this orignal bolt badly 'chewed' and the hex faces badly rounded.  This of course means the carb is far more likely to not get fully tightened - often leading to wear of the carb bore, and meaning air can enter from the stub and affect the running of the engine.

As well as the distinctive sthape and profile of the bolt - we CNC mill the hex head to the correct imperial spanner size of  1/8" Whit (we mill this head, as it is becoming increasingly difficult to obtain it in stainless steel), which gives a very crisp finish - important, as it is often this hex head that suffers on original carbs - as they are often overtightened with use.   We emphasize this - because having personally experienced the annoyance at having to try and continually tighten an original bolt, where years of abuse has 'Rounded' the original head of a Type 276 carb, it is a pleasure to fit a bolt that allows a close fit of the correct spanner!

As a final design point - we have also replicated the opposite threaded end on these small bolts - which was rounded, as it protruded from the threaded end of the ring - presumably to avoid it catching on cloth's when the owner cleaned the bike.

Top ring retainer spring as fitted behind lockring of bellmouth on original later type Amal TT carbs, and stops top lockring from loosening.  This one, as per original item, in plated spring steel.  

Note : earlier Amal TT (and all RN type) carburettors used a different method of locking the top ring - this being a brass type top cap with a square headed screw in the top of it, that when tightened down, pushed out a lock pin that gripped against the inner face of the threaded top ring.  These are often identifiable - because the inner top ring will often have score marks where a previous owner has tried to unscrew the top ring without loosening the square headed screw!

Sorry, but we do not offer a reproduction of this earlier type mixing chamber top cap (although we do sell the wider distinctive throttle cable adjuster that fitted in them - see Item 0874, which also shows an example of the earlier top), but we do sell the later top cap that was used in conjunction with this spring - Item 0138.  If you are not sure which type of TT carb body you have - then the TT carb to accept this type of leaf spring will have a small indent underneath the main body casting at the point the bellmouth screws in, this is to accept the spring 'stop' and ensures the spring does not rotate while you are unscrewing the top.  This is shown in the second photograph.

If you have the earlier type carb, but the carb top (mixing chamber) is no longer working - the small indent mechanism often jams, then it is possible to fit this later type of spring to stop the threaded ring coming loose, but you would either have to grind off the small tab at the base of the circle of this spring (my preferred method), or mill a small slot in the base of the carb body as per photo.  In reality, the tightened bellmouth lock ring should be enough to keep the spring in place when unscrewing/screwing the top ring - but I know I have just held it with my fingers in the past, to stop it trying to rotate.

Update May 2020:  Just had a new delivery of these, and have actually been able to reduce price slightly due to having a much bigger batch made this time

- 'Short' type bellmouth to fit original Amal 10TT carburettors .  High quality CNC machined from an original bellmouth pattern.  Available in various internal diameter's - including those to fit both 350 and 500 variation SOHC Nortons 

These distinctive bellmouths are of the type originally fitted to Amal 10TT competition carburettors and were most commonly fitted to roadgoing Norton SOHC models as well as many other British competition and sports motorcycles throughout the 1930's - 50's.

These are CNC machined from an original bellmouth pattern and are available in various internal diameters from 1 3/32" (350 Norton International size) to 1 3/16" (the largest commonly available 10TT size, although in the past I have made a couple of up to 1 1/4"  which I believe was a special size occasionally made - I have fitted one of these to a methanol SOHC engine in the past).

Standard Norton International 500cc size was 1 5/32", although for earlier engines up to 1935 the size was 1 1/8".  We offer both these sizes.

SOHC Manx engines were normally fitted with Amal RN engines from the late 1930's.  Although I believe these were sometimes fitted with 'Short' bellmouths, it was more normal to see these fitted with 'Medium' length bellmouths.  As at 25/6/18 we have ran out of these medium length bellmouths, but expecting to have a batch available in the next 4 weeks - email us at normal 'Sales' email to reserve one

- 'Medium type bellmouth to fit original Amal 10TT and RN (Remote Needle) carburettors .  High quality CNC machined from an original bellmouth pattern (see photo) .  Available in various internal diameter's - including those to fit both 350 and 500 variation SOHC Nortons 

These distinctive bellmouths are of the type originally fitted to Amal 10TT and RN competition carburettors and were the type often seen fitted to early SOHC 30M/40M SOHC (and early DOHC) Manx Norton's fitted with Amal RN carburettors throughout the 1930's - 50's.  They were also fitted to many other competition and GP bikes of the 1930's-1950's.

These bellmouths are CNC machined by us from an original bellmouth pattern.  The first photograph shows  a very original longnecked (as fitted to SOHC racing Norton's) Amal RN competition carburettor (still with original paint), fitted with one of our CNC machined bellmouths, and the original Amal RN bellmouth in front of it.  I hope you would agree - the profile and overall shape of our bellmouth is pretty much identical to the original  . . . while most other 'medium' length pattern bellmouths I have seen manufactured over the years have not been able to get this profile correct.

They are available in various internal diameters from 1 3/32" (350 Norton International size) to 1 3/16" (the largest commonly available 10TT size, although in the past I have made a couple of up to 1 1/4"  which I believe was a special size occasionally made - I have fitted one of these to a methanol SOHC engine in the past).

Standard Norton International 500cc size was 1 5/32", although for earlier engines up to 1935 the size was 1 1/8".  We offer both these sizes.

SOHC Manx engines were normally fitted with Amal RN engines from the late 1930's.  Although I believe these were sometimes fitted with 'Short' bellmouths (see Item 0140a), but it was more normal to see these fitted with 'Medium' length bellmouths.  However, I have also seen roadgoing models with Amal TT carburettors fitted with the longer 'Medium' length bellmouth - we do both, whichever is your personal preference.

These medium length bellmouths will also fit the later Amal 15GP or 10GP competition carburettor (but not 5GP or 3GP which are larger).  It is not unusual on later GP carburettors to see a slightly  more cone shaped  profile, rather than the type shown here for RN/TT type carbs, although this is only obvious when compared side by side

Final point:  I also offer a 'Custom Diameter' - which means if you have a particular diameter not listed, I may be able to machine this with some change to our program - but may have an additional cost, as i would need to set machine up for doing this task - email us on normal sales@racingvincent.co.uk

- Long type bellmouth to fit original Amal 10TT and RN (Remote Needle) carburettors. Can also be fitted to  10GP1 .carbs  High quality CNC machined from an original bellmouth pattern (see photo) .  Available in various internal diameter's - including those to fit both 350 and 500 variation SOHC and early DOHC Nortons 

These distinctive bellmouths are of the type originally fitted to Amal 10TT and RN competition carburettors and were the type often seen fitted to early SOHC 30M/40M SOHC (and early DOHC) Manx Norton's fitted with Amal RN carburettors throughout the 1930's - 50's.  They were also fitted to many other competition and GP bikes of the 1930's-1950's.

These bellmouths are CNC machined by us from an original bellmouth pattern.  The first photograph shows  a very original longnecked (as fitted to SOHC racing Norton's) Amal RN competition carburettor, fitted with one of our CNC machined bellmouths, and the original Amal Long neck RN bellmouth in front of it.  I hope you would agree - the profile and overall shape of our bellmouth is pretty much identical to the original  . . . while most other 'Long' length pattern bellmouths I have seen manufactured over the years have not been able to get this profile correct, most showing the type later fitted to Amal GP2 carburettors, which were more funnel shaped, than the distinctive 'parrallel neck' bellmouth fitted to TT and RN carbs.

They are available in various internal diameters from 1 3/32" (350 Norton International size) to 1 3/16" (the largest commonly available 10TT size, although in the past I have made a couple of up to 1 1/4"  which I believe was a special size occasionally made - I have fitted one of these to a methanol SOHC engine in the past).

Standard Norton International 500cc size was 1 5/32", although for earlier engines up to 1935 the size was 1 1/8".  We offer both these sizes.

SOHC Manx engines were normally fitted with Amal RN engines from the late 1930's.  Although I believe these were sometimes fitted with 'Short' bellmouths (see Item 0140a), but it was more normal to see these fitted with 'Medium' length bellmouths.  However, I have also seen roadgoing models with Amal TT carburettors fitted with the longer 'Medium' length bellmouth - we do both, whichever is your personal preference.

These Long length bellmouths will also fit the later Amal 15GP or 10GP competition carburettor (but not 5GP or 3GP which are larger).  It is not unusual on later GP carburettors to see a slightly  more cone shaped  profile, rather than the type shown here for RN/TT type carbs, although this is only obvious when compared side by side

Final point:  I also offer a 'Custom Diameter' - which means if you have a particular diameter not listed, I may be able to machine this with some change to our program - but may have an additional cost, as i would need to set machine up for doing this task - email us on normal sales@racingvincent.co.uk

This is a replacement for Amal TT or RN bellmouth if you want to use the bike on the road and are concerned about ingestion of dirt or grit - which some people are, as the standard Amal TT/RN type bellmouth is open to the elements.

The inlet is CNC machined from the same alloy billets as the 'Short TT Bellmouth' (Item 0140A) we also offer, but in the case of this type - the outer curved lip of the original bellmouth is changed to a flange, allowing snug fit of a cone type filter.

The cone is a commercially available 'Pit Bike' filter with  .  It has a 'standard' short type TT/RN inlet tract and thread with a modern 'Pit Bike' cone type filter fitted.  In some of the attached photographs the chrome of the cone filter looks blue - this is the plastic protective film supplied with the cones to protect the chrome and should be peeled off after fitting.   

These are CNC machined and are available in two bore sizes: Standard Norton International 500cc size - 1 5/32", and also 1 3/16" bore size (which is another popular size in our normal TT/RN bellmouth range) and the largest normal bore size that original Amal TT and RN carbs were supplied with). State which size you require in the comments section when ordering.

FYI - I would expect that the bore size is far less critical on this type of bellmouth, i.e. in case you have a slightly smaller bore size, such as 1 3/32" etc. - Normally the bellmouths on Amal TT (and other competition) carbs were blended with the carb size exactly - to assure maximum efficiency at maximum racing speeds.  For those fitting this type of bellmouth/filter . . . normally on the road, to offer some engine protection from grit etc - you should expect that this carb setup is no longer going to be suitable for maximum competition performance (and a level of re-jetting may be necessary anyway)

It should be noted that these filters (as fitted to pit bikes) look to be of the gauze and thin filer material type, and although good value - they are not the K&N washable paper filter type - which would make the unit far more expensive.  However, if you wish to fit a K&N style filter yourself at a later stage - then I believe the RC-790 K&N Model is a likely fit (email to confirm details of bore  etc if you are considering this) and should have the same fittings. Note though - when I checked retail prices of this model of filter in the UK, as part of making these units - I found the price of the filter alone in excess of the retail price of the entire unit shown here.

Fitting Instructions and Jetting:

Just as with normal bellmouths to fit original Amal TT or RN carbs, these bellmouths have a thread that screws into the main body and will also use the standard TT/RN lockring (so you should be able to use the one from your existing bellmouth, or we can supply seperately - Item 0142).

It goes without saying that - just as you would when fitting any original Amal TT or RN carburettor to your motorcycle for the first time - if fitting one of these filters, you should check the settings yourself to confirm if re-jetting is required (i.e. Main Jet or Pilot Jet) - as this can vary a great deal from one engine to another, and is also dependent on the condition of the original carburettor.  We recommend following the normal procedure for tuning an Amal TT or RN carb to satisfy yourself it is correct - and re-jet as necessary.  If you do not feel you have necessary experience or would not want to do this - then we recommend not purchasing this item and continue instead with the original open bellmouth

- Lock ring to fit original Amal 10TT, RN and some GP carburettor bellmouths.  These alloy lockrings are CNC machined copying an original Amal TT pattern for reference.  

- These lockrings are intended to fit Amal competition carburettors and help lock the bellmouth in place. On post-war TT carbs, it serves a dual purpose of locking the cap ring retainer spring.  They have a 1.5" diameter internal thread and were fitted to all 10TT and RN10 carburettors as well as GP carburettors with the same bellmouth outer diameter

- These - Helpful hint : to correctly fit these, buy a Girling shock absorber adjuster C-Ring spanner, then file the tang on the smaller C, it will be the perfect tool for locking these without damage to the ring

- This is the small threaded peg that locates the throttle adapter body in the main choke barrel on Amal TT carburettors - originals always seem to be rusty or chewed

These are CNC machined in stainless steel from an original pattern

This is the special needle carrier that were attached to the slide on original Amal RN competition carburettors - allowing the throttle needle to be held remotely from the throttle slide.  CNC machined to the original pattern

This fitting is particular to the Amal RN (Remote Needle) model, and as far as we are aware have been unavailable for many years.  Ours are CNC machined from solid brass billet to the exact dimensions of the original item - including the fine slot for the needle spring clip (Item 0960) and the counterbored screw hole at the top, which allows this clip to be attached to the throttle slide.

We also include the special brass screw that was used to fit these to original slides - which should be flush fitting at the top, so they did not foul the carb top cap.  Email us if you require further information on the the thread and length of this screw - and if fitting this to a new slide - carefully ensure the thread in the slide and screw are the same and a smooth fit - before fully tightening home.

Note: If you own an original Amal RN carburettor, you have probably looked at the slide and wondered how this needle carrier was held to the slide.  It is important to note that it was not retained purely by the screw (which we believe to be a 5/32 x 32tpi BSW thread) - the RN slide also had the needle holder screw hole counterbored underneath, then when the barrel headed screw was fully tightened, the head of the thread was peened into the counterbore so it could not loosen and come away from vibration in use. Added to this, at least two original RN slides I have stripped have also had the brass needle holder soldered to the slide in addition to the screw (but i am not sure if this was done for all slides).

Therefore, if fitting one of these needle holders to a standard Amal TT slide - it is important to bear in mind the original method of attaching, and satisfy yourself that you have fitted the needle holder securely before use.  We also sell complete Amal RN Throttle Slides already (jig) fitted with this special arm, in various slide cutaways - See Item 0961.  These are not cheap - but the arm is already fitted in the same manner as the original items

Note: we can supply high quality slides already fitted with these needle holders in No5 and No6 cutaways if required - Item 0961