This listing shows the various pipe fittings we can supply to fit the 1/4" outer diameter oil and petrol pipe fittings as used on the Douglas 2 3/4hp models (and other early Edwardian machines).  Most of the nuts are CNC manufactured in stainless steel, and the ferrules in brass.  

As background to this listing, when restoring my own 1919/20 Douglas 2 3/4hp model (as shown in photographs), I found that the pipe fittings, as fitted to the original hand pump and drip feed oiler to the engine were mostly unavailable commercially.  Therefore after conferring with other owners on the Douglas forum - to confirm the original oil pipe diameter was 1/4" outside diameter, we have manufactured the various fittings and pipes to make up a full oil feed assembly, as well as the engine drain breather pipe.

The parts listed below can all be ordered individually from this listing (select the sub item to order), or as a full assembly (at a similar price to buying individually, but we have pre-formed and soldered pipes/ferrules to our templates on our own pipe bending jig). 

Note:  As I write this update (Aug 2020), pipes are supplied in base copper unplated.  I will look to be having some plated in a bright nickel finish shortly - email for update on sales@racingvincent.co.uk.  Likewise, I will also be adding petrol pipe assemblies shortly - but these may only be relevent to the Douglas Amac carb fitted to my own model - again, email if more details required.

The parts we can supply are as follows (prices are for 'each' unless otherwise stated):

This is the distinctive petrol tap and filter unit that were fitted to Douglas models from 1914 - 24.  The tap itself is a good quality brass taper tap with 1/8" BSP thread into the tank - as per the original item.  The filter unit is CNC machined stainless steel with screw in seperate filter and 1/4" BSP thread outlet.

Update May 2023: A new batch now back in stock.

Background and Manufacture:

The original Douglas 2 3/4hp petrol tap with filter unit (original Part Number 1185d) had a distinctive look and according to the original Spare Parts catalog was fitted to all models from 1914-24 (a plain tap without filter is listed for 1912-13, but I have also seen pictures of pre WW1 bikes with them fitted - not sure if these are original?).  

When rebuilding my own 1919 Douglas 2 3/4hp model, although I have a lovely original petrol tank (still in its original paint), I did not have the correct petrol tap, so looked to replicate this unit, using period photographs.

The starting point is an excellent quality brass lever tap, manufactured by one of my suppliers, which has the correct 1/8" BSP thread into the petrol tank and 1/4" BSP outlet, but no filter fitted.  It also has a gauze filter fitted, going into the fuel tank.

The only change made to these taps is to strip and re-machine the lever boss to give them a more authentic and original look. We then polish the brass and reassemble it.

The filter unit is manufactured by ourselves, being a screw on filter cylinder, to accept a small conical gauze filter (fitted), then red fibre unit, and then a screw in bottom ferrule to secure the filter - the outlet of this being standard 1/4" BSP thread with taper.  This filter unit is CNC manufactured in stainless steel and is supplied fully assembled to the brass petrol tap, ready to fit. However, the filter unit can be stripped for cleaning if required. a 1/8 BSP red fibre washer is also included.

If required, the small cone filter inside the filter unit can be omitted - as the main petrol tap unit also comes with gauze filter supplied.

Note: Dec 2021: As supplied to me, the base fuel taps are manufactured in brass and unplated, I then re-machine the tap shaft to give a more authentic/period shape before polishing and reassembling the tap and fitting the parts we manufacture.  I did originally consider getting these taps nickel plated - so the whole unit looked similar - but actually the polished brass against the polished stainless (that looks like period nickel plating) looks really attractive - but most importantly, when fuel tap cocks are plated they invariably leak - which in my opinion is a good reason to leave them as they are , hope you understand!

This item listing is for a length of 1/4" outer diameter copper fuel (or oil) pipe of 420mm (approximately 16.5" inches), which is long enough to make a petrol pipe for most Douglas 2 3/4hp / 4hp variants or other similar Edwardian bikes.  

These copper pipes are pre-cut straight lengths of 1/4" diameter copper fuel pipe (from a trusted UK supplier we use for all similar copper pipe supplies) - which will allow you to easily bend the pipe to the desired shape for your own Douglas 2 3/4hp or 4hp model variant.  As you can see from the accompanying photographs - I have also shown a picture of a similar length of the same copper pipe, which I have bent to fit my own 1919/20 Douglas 2 3/4hp model.  I believe this particular shape is one of the most common seen on those 2 3/4hp models using the Amac carb type shown in the photo.

Because there are so many variants of carburettor/petrol tank/petrol tank combinations, there is little point us offering pre-bent pipes - but rest assured, these pipe lengths are easy to bend to shape - and can even be done with firm finger pressure.  However for best results - I use a small pipe bending hand tool (easily found on E-bay), or sometimes just gently bend around a piece of aluminum or steel bar stock with the correct radius.  The pipe comes to us in large reels (pre-annealed I believe), so should not require further heating before bending.

If possible, I would advise starting the pipe a fraction longer than the final length, and then that extremity can then be held in a vice, or up against a 'stop' of some sort, to allow extra leverage for any bends close to the end.  It can then be cut to final length.  I use a small angle grinder with a thin cutting disc for cutting off (you will find this much easier than a hacksaw) then finely linish a chamfer on the outer face and de-burr the inner face.  Finally - remember to blow any swarf particles from the pipe after de-burring, particularly if using this pipe as an oil pipe.

I believe this diameter of copper pipe was used on many belt drive and Edwardian motorcycles, and we can also provide a variety of fittings and ferrules to fit this pipe (soft soldering is normally sufficient to provide a firm joint, but ensure you use plumbers solder, not electrical solder).  For the standard 1/4 BSP and brass tapered ferrule see our Item 0891_4.  If you are fitting this fuel pipe to an Amac carburettor with the float chamber similar to the one shown in these photos - then we also manufacture the ferrule and stainless nut to fit that carburettor type - Item 0982.

We can also provide custom lengths of similar pipe - expect price to be pro-rata based on length of this.  Email on sales@racingvincent.co.uk to enquire

This item is an amended (lipped) type of bottom main jet holder, to fit early Amac carburettors - i.e. the HYK type, as fitted to Douglas 2 3/4hp Models (as listed 1919-21 as part number 1644D).  The same jet holder may have also been used in other similar Amac carbs of the period 1912-25.

The original Amac type main jet nut design relied on a very narrow chamfer to create its seal, when screwing it in to secure the float chamber, which does not seem a particularly good design - especially when you consider that the original Amac float chambers (as shown in the photos) that were sold with these carbs had a nicely machined flat bottom face - just crying out for a seal with a red fibre washer, which of course, was what many other later Amal designs employed to secure floatchambers.  

Certainly - when restoring my own 1919/20 Douglas 2 3//4hp model, I found that the original (and mostly unmolested) Amac HYK carb that came with it, had a particularly graunched main jet, and although I did initially try to reclaim it - it continued to leak heavily.  I also have a second similar original carburettor - where the original plated main jet nut is shown in the photos.  This is still in good condition - but when I examined it closely, I could see how narrow the sealing chamfer looked - so decided to make a small batch of nuts, as shown here - which are instead CNC machined from 0.875" brass bar, so that although identical in most other respects - they now offer a large 0.875" wide lip, that allows for a wide red fibre washer  between nut and float chamber, to prevent leaking.

It should be noted that special attention was paid to ensuring that when using the red fibre washer (supplied), the final position of the main jet, in relation to the main Amac carb body should be the same as the original Amac main jet nut.

We use high quality red fibre washers from one of the top manufacturers, and two will be supplied with each nut - although only one washer should be fitted - the other being a spare (the top face of Amac floatchambers do not need a washer - they rely on a taper, which mates with a similar taper on the main carb body).

Price is for (satin nickel plated) brass jet nut and 2 red fibre washers (the original Amac main jet shown in some of the photos are not included in the sale)

Update October 2022:  These items have now been Satin Nickel Plated - as would have been the original finish.  Some of the photographs for this item were taken before plating (i.e. bare brass - but the item you are ordering will come Satin Nickel Plated

Price reflects complexity of CNC setup for this item (approx 12 different tooltype/multiple ops required!) and small batch number produced.

This listing is for a bottom floatchamber nut and brass ferrule to fit early Amac carburettors of the type commonly fitted to Douglas 2 3/4hp and other belt drive models of that era.  The nut is CNC machinined in stainless steel, while the ferrule is brass (with Amac sharp taper) to accept 1/4" bore copper pipe.  

As can be seen from the accompanyning photogrpahs, this listing is for a float chamber base nut and ferrule to fit early Amac carburettors with the floatchamber that has a bottom petrol feed of the type shown here.  This type of carburettor was commonly fitted to Douglas 2 3/4hp models, but I am sure were also fitted to a variety of other early motorcycles up until the late 1920's.

I have two or three of these early carburettors, but the one that was fitted to the current 2 3/4hp model I am building did not have an original float chamber bottom nut - so rather than taking one from another carb, and leaving that short - I took the original nut/ferrule from another carb as a pattern and wrote the CNC programs to make a batch.  I found that the unions on these early Amac carbs are very different to most later Amal carbs (which pretty much standardised fuel pipe attachment unions as being 1/4" BSP, and the standard hex that went with that - which can be seen on the accompanying photograph of the made up fuel pipe - on the union that would fit to the fuel tap).  Instead, the union nuts on these earlier Amac carbs were a larger hex, the thread was a fine thread (BSC size), not BSP, and most importantly - the taper on the bottom of the float chamber, where the brass ferrule inserts, is a steeper angle than later BSP ferrule fittings.

The original Amac nut is shown in the first photograph on the left of the new nuts we have manufactured.

As you can see - these nuts are CNC machined in stainless steel (which looks almost indistinguishable from bright nickel plating used on earlier Edwardian bikes), and have the flats lightly linished - so as well as fitting nicely, they also look pretty.  The brass ferrule has the sharper taper required to fit the Amac floatchamber, and is bored to accept 1/4" bore copper fuel pipe as would have originally been fitted to these carbs (see Item 0981).  

Price is for one stainless nut and one brass ferrule (pair)

This item is for a pair of high quality red fibre washers - which are an exact fit on the modified/lipped main nut (Item 1095) we offer to fit early Amac HYK carbs - please read item 1095 description before ordering these, and note that if ordering the 1095 nut - it already comes with a pair of washers, this listing is just for a pair of washers on its own.

Note that (although I am no expert on early Amac carburettors) - the original Amac bottom nuts of pre-1920 era I have seen do not have a lip - and no washers were use - it just relied on a very shallow taper on the nut - which was easily damaged and leaked, hence why we manufactured the modified lipped nut.  However, this design seemed so likely to receive damage and leak.. . . it would not suprise to know that later (1920s) Amac or similar carbs used a lipped bottom nut (as indeed later Amal carbs did).

However, if you require spare washers for these Item 1095 nuts . . . or think you have another carburettor which requires similar size red fibre washers - then here are dimensions of these washers:

Inner Diameter = 14.2mm.  Outer Diamter = 23.5mm. Depth = 1.4mm

These are high quality vulcanised red fibre washers, sourced from our specialist washer manufacturer.  Price is per pair.

This is a 1/4 BSC (26tpi) shouldered bolt of 1.00" shaft length, with the distinctive shouldered square head, of the type used on brake assemblies of early Douglas 2 3/4hp models.  It is intended to feed through the brake rod square clevis - and then screw into the original Douglas brake pedal, then a locknut is used on the opposite side to retain it.

Consists of bolt, 1/4" x 26tpi BSC nut and two 1/4" washers, all in Stainless Steel.

I have made a small batch of these bolts as part of the restoration of my own Douglas 2 3/4 hp model, of which I am building as a 'loose' copy of a sports/racing version of this model - a Works model of which Douglas won the Isle of Man Junior TT with in 1912.

I copied this bolt from an original item which was part of a very rusty but original early Douglas front brake assembly - which I am almost certain was of the type of assembly fitted to the 1910-1912 models, to the front downtube.  I have seen a very similar assembly and brake pedal fitted to period photos of this model - where it was not uncommon to have a two sets of footrests, the normal set just in front of the two speed countershaft, and another forward positioned assembly mounted at the base of the front down tube.  

When purchased this front brake assembly was very rusty and dilapidated - but looked original and unmolested.  The assembly included the brake pedal (see accompanying photos), original Douglas brake positioning lock ring and square headed bolt for that locking (see Item 0689/690) and what looked to be original but very rusty brake rod with square clevis and square headed bolt for attaching the brake rod to the threaded brake pedal- which is the item shown here.

Although the square headed bolt was very dilapidated, I was able to de-rust it and used it as a template for CNC machining a copy in stainless steel, including lipped square head, which has been milled from round bar.  The thread is 1/4" BSC (26tpi) and each bolt comes with a nut and two washers also in stainless steel.  If I say so myself they look rather nice, wont rust, and when polished look just like the original nickel (pre-chrome) plating!

Final Note (29/03/18):  I know that Douglas employed some unusual and non-standard threads in this Edwardian period.  I have made this particular bolt in 26tpi (threads per inch) x 1/4" BSC because nuts are available in this size and I was easily able to run a thread cleaning tap of 26pi (BSC) down the female brake pedal thread.  I will use the locknut supplied to run up against the brake pedal to ensure locked correcty.  However I suspect the original bolt may be a weird Douglas 25 tpi x 1/4"  thread, but is not in very good condition.  Please measure your original brake pedal thread/bolt to ensure you know the correct thread before ordering.  It is CNC manufactured in stainless steel

if you are not sure (the difference between 26tpi and 25tpi is very close) and have the original bolt - then try and run a 1/4 BSC nut down the thread of your original bolt - if it tightens up as you start, it may be a 25tpi bolt.  Alternatively - hold a 1/4BSC bolt up against the thread of your original douglas bolt - if one thread does not exactly sit in the other, this is another way to tell.

If you think your bolt is a Douglas 25tpi x 1/4" thread - then I have also made a small batch of this alternative type: see Item 0688

This is a shouldered bolt of 1.00" shaft length, with the distinctive shouldered square head, of the type used on brake assemblies of early Douglas 2 3/4hp models.  It is intended to feed through the brake rod square clevis - and then screw into the original Douglas brake pedal, then a locknut is used on the opposite side to retain it. This item is an alternative to item 0687 - in that it has a Douglas 25tpi thread instead of 26tpi BSC thread used on item 687.  Please measure your original brake pedal thread/bolt to ensure you know the correct thread before ordering.  It is CNC manufactured in stainless steel

I have made a small batch of these bolts as part of the restoration of my own Douglas 2 3/4 hp model, of which I am building as a 'loose' copy of a sports/racing version of this model - a Works model of which Douglas won the Isle of Man Junior TT with in 1912.

I copied this bolt from an original item which was part of a very rusty but original early Douglas front brake assembly - which I am almost certain was of the type of assembly fitted to the 1910-1912 models, to the front downtube.  I have seen a very similar assembly and brake pedal fitted to period photos of this model - where it was not uncommon to have a two sets of footrests, the normal set just in front of the two speed countershaft, and another forward positioned assembly mounted at the base of the front down tube.  

When purchased this front assembly was very rusty and dilapidated - but looked original and unmolested.  The assembly included the brake pedal (see accompanying photos), original Douglas brake positioning lock ring and square headed bolt for that locking (see Item 0689/690) and what looked to be original but very rusty brake rod with square clevis and square headed bolt - which is the item shown here.

Although the square headed bolt was very dilapidated, I was able to de-rust it and used it as a template for CNC machining a copy in stainless steel, including lipped square head, which has been milled from round bar. 

Note:  see also item 0687 description.  When I copied the original Douglas bolt I used as a pattern - it was 1/4" x 26tpi BSC - which is Item 0687.  However, some bolts of this period look to have been 25tpi (see also the shorter brake pedal adjusting ring bolt - item 0688, which is also of 25 tpi is an example of this).  But I made a small batch of the longer 'item 0687' type brake rod bolts - but with the Douglas type 25 tpi x 1/4" thread instead, in case you believe your bike is fitted with this thread.

if you are not sure (the difference between 26tpi and 25tpi is very close) and have the original bolt - then try and run a 1/4 BSC nut down the thread of your original bolt - if it tightens up as you start, it may be a 25tpi bolt.  Alternatively - hold a 1/4BSC bolt up against the thread of your original douglas bolt - if one thread does not exactly sit in the other, this is another way to tell.

Unfortunately, I do not offer 25 tpi Douglas thread nuts to fit this bolt - so this listing is for the bolt only.  As this bolt is intended to feed through the Douglas 2 3/4hp brake rod clevis and then screw into the original Douglas brake pedal, you will need to keep hold of your original locknut if you still have it! 

This is a shouldered bolt of 0.710" shaft length, with the distinctive shouldered square head, of the type used on brake assemblies of early Douglas 2 3/4hp models.  It is intended to feed through the circular locking ring used on early Douglas 2 3/4hp brake pedal assemblies, which is used to adjust the position of the brake pedal on its shaft. This bolt has a  Douglas 0.257" x 25tpi thread, as per the original bolt used as a pattern.  Please measure your original brake pedal lock ring thread/bolt to ensure you know the correct thread before ordering.  It is CNC manufactured in stainless steel

I have made a small batch of these bolts as part of the restoration of my own Douglas 2 3/4 hp model, of which I am building as a 'loose' copy of a sports/racing version of this model - a Works model of which Douglas won the Isle of Man Junior TT with in 1912.

I copied this bolt from an original item which was part of a very rusty but original early Douglas front brake assembly - which I am almost certain was of the type of assembly fitted to the 1910-1912 models, to the front downtube.  I have seen a very similar assembly and brake pedal fitted to period photos of this model - where it was not uncommon to have a two sets of footrests, the normal set just in front of the two speed countershaft, and another forward positioned assembly mounted at the base of the front down tube.  

When purchased this front assembly was very rusty and dilapidated - but looked original and unmolested.  The assembly included the brake pedal (see accompanying photos), original Douglas brake positioning lock ring and square headed bolt for that locking - which is the item copied here - CNC machined with a shouldered/milled square head in stainless steel

Although the square headed bolt was very dilapidated, I was able to de-rust it and used it as a template for CNC machining a copy in stainless steel, including lipped square head, which has been milled from round bar. 

This particular bolt is of a very unusual dimension - 0.257" diameter x 25tpi (threads per inch), but I measured it carefully from the original bolt (the original Douglas bolt - shown in one of the accompanying photos next to the CNC manufactured version), and once manufactured, fitted it to the original lock ring - where the thread fitted perfectly.  I myself am surprised the thread diameter is slightly oversize from the more traditional 0.250" diameter - but I did make a sample one at 0.250" as a comparision - and the 0.257" is definitely a better fit into the lockring - so I believe it to be correct.

If I say so myself this bolt is very pretty, when polished looks almost indistinguishable from the original nickel plating of this era and will not rust!  And probably the first 25tpi bolts made for many years!

Note:  see also item 0690:  Just in case you think your own locking ring is the more standard BSC 26 tpi thread - I have also made a small batch of these bolts, but with a 26tpi thread.  

This is a shouldered bolt of 0.710" shaft length, with the distinctive shouldered square head, of the type used on brake assemblies of early Douglas 2 3/4hp models.  It is intended to feed through the circular locking ring used on early Douglas 2 3/4hp brake pedal assemblies, which is used to adjust the position of the brake pedal on its shaft. This bolt is an alternative to Item 0689 - it having a  a 0.257" x 26tpi BSC thread.  Please measure your original brake pedal lock ring thread/bolt to ensure you know the correct thread before ordering.  It is CNC manufactured in stainless steel

I have made a small batch of these bolts as part of the restoration of my own Douglas 2 3/4 hp model, of which I am building as a 'loose' copy of a sports/racing version of this model - a Works model of which Douglas won the Isle of Man Junior TT with in 1912.

I copied this bolt from an original item which was part of a very rusty but original early Douglas front brake assembly - which I am almost certain was of the type of assembly fitted to the 1910-1912 models, to the front downtube.  I have seen a very similar assembly and brake pedal fitted to period photos of this model - where it was not uncommon to have a two sets of footrests, the normal set just in front of the two speed countershaft, and another forward positioned assembly mounted at the base of the front down tube.  

When purchased this front assembly was very rusty and dilapidated - but looked original and unmolested.  The assembly included the brake pedal (see accompanying photos), original Douglas brake positioning lock ring and square headed bolt for that locking - which is the item copied here - CNC machined with a shouldered/milled square head in stainless steel

Although the square headed bolt was very dilapidated, I was able to de-rust it and used it as a template for CNC machining a copy in stainless steel, including lipped square head, which has been milled from round bar. 

This particular bolt is an alternative to item 0689 - in that it is is still of 0.257" diameter (as per item 0689), but has been manufactured with a more common 26tpi BSC thread - in case your lockring has been re-tapped with a BSC thread.   Read item description for 0689 before ordering this part - I am not sure if Douglas later manufactured this bolt in a 26tpi thread - but in case they did, I have also made a small quantity of the bolt in this listing - which is the same dimensions as Item 0689, except it is made with a 26tpi thread.   

If I say so myself this bolt is very pretty, when polished looks almost indistinguishable from the original nickel plating of this era and will not rust!  

Note:  see also item 0689