This listing shows a selection of brass fittings for veteran motorcycle spark plugs, as well as some rarer spark plugs and fittings (and a nice copy of the Veteran Lodge style brass cooling fins that fit over most spark plug types).  We have manufactured the knurled brass nuts for securing the HT lead on older motorcycles (i.e. pre spark plug cap) in two main styles and a variety of threads.

Note: see also Item Listing 0896 - since originally starting this multi-item listing, I have now listed our 18mm KLG type spark plugs seperately, along with 18mm/14mm copper abestos type spark plug sealing washers.

Spark Plug HT Lead Nipple/Knurled Nut Background:

If you have an older historic motorcycle - i.e. pre WWII or earlier, then you may decide you wish to fit the HT lead to your spark plug with a brass connector, rather than with a more modern HT Spark Plug Cap (of which we also sell in various styles).

Like many old motorcycle enthusiasts, over the years of collecting I have accumulated a selection of old spark plugs of various styles, and some of these go back to the earliest motoring days of the 19'teens - 1920's.  When recently I was looking to fit spark plugs to my own 1919 Douglas 2 3/4hp project bike (used for some of the photos in this listing), I decided to fit period 18mm spark plugs and our ochre coloured cloth/waterproof HT lead, along with veteran style brass HT clip connectors (i.e. pre plug cap) - which would have been correct for a veteran bike.

To go with this I investigated the different style of knurled screw on nuts which were commonly fitted to these early type of plugs, which allow the brass HT connectors to be easily screwed on our taken off.  I was suprised to find there were lots of styles and variations over those early days - but by far the most common type was the knurled adjuster with a design commonly seen fitted to Champion spark plugs.

However, I also have an example of a very pretty Lodge type of knurled nut - which has a wider top knurl diameter and a concave tope.  As well as giving good purchase when tightening the HT lead to the plug - I think this type of knurled is very pretty, and quite rare now.n

Therefore - we have replicated  both these definitive styles - the bigger diameter Lodge type being an almost identical copy of the original nut, while the other small type is copied from an original definitive type used on a 1920's Champion plug (note - I found numerous nuts of this style, many with minor variations over the years - but chose an early type of the most definitive design).

Both knurled nut types are CNC machined in brass by us and can be supplied in a variety of threads - the sub listing items representing the most commonly used spark plug top threads used.  

Early Spark Plug Brass Cooling Fin - based on Lodge original, to fit most spark plug types (0895_8):

As you can see in the first photo, in my spark plug collection I have an unusual and very pretty/rare pink Lodge H1S spark plug (New Old Stock), which has the addition of a brass cooling cap with fins, which sits atop the porcelain.  I have seen similar brass cooling fins fitted to the very earliest (i.e. Edwardian) motorcycles and cars and they give a lovely period look to an older motor vehichle restoration.

We have reproduced this finned cooling ring - to an almost identical profile, but underneath, the ring counterbored so that it will fit on top the porcelain of almost any spark plug - including modern plugs.  By so doing, if you wish, you can use modern spark plugs (with make scrubbed off if required!) and this ring placed on top of the porcelain to give the plug a much older and pretty look. 

We offer this cooling ring, along with the knurled 'Lodge' type HT nut (specify which thread type for nut when ordering)  - as shown in the photos associated with this item - including them having been fitted to the KLG 18mm ML50 plugs we also offer here, fitted to my own Douglas 2 3/4hp project.  I have to say, they nicely finish off this area of the restoration.

Spark Plug Top Thread Background:

Until we came to make these knurled HT nuts, I had always assumed the top thread used to hold the HT nipples on spark plugs was a standard thread - standardised on all spark pluge going back to the earliest days - No such luck!

It turns out there were numerous threads used over the years - and I do not think we have found them all!, however I think we have identified the 4 main types (and two seem most commonly used), and have made the two knurled nut styles in sub-types to take into account the different thread types.

I have also gone through my own spark plug colletion and tried to identify the different Makes and Styles that used the different thread types - I cannot be sure that if you have the same spark plug in your collection, it will have the same thread (as they may have changed by year) - but in the accompanying photographs, I have showed some of the plugs with their various thread type in the sub listing to help you select which one is right for your plug.

If not sure - I would suggest you buy one of each (!) . . . but do not try and force on by more than two threads or the brass may strip.  

I cannot be sure this is definitive - but in general I found the following threads used on the following plugs (see photographs that accompany the individual items):

- 8 UNC Thread (0895_1 and 0895_4):  

  - Champion:  I found a number of the older (or US branded?) Champion plugs fitted with this metric 8 UNC Thread.  Those tried with this thread included: Champion N5 (common 14mm 1960's - 1980's plug/ C5 (22mm plug) - both early 1930's rounded ceramic type and later (1960s style multi ridged type) / J10-COM/ L7 (another 14mm 1960s style plug)/ D8C - this last plug is a rare 18mm long reach plug with an unusual extended 3 prong electrode - they are a possible alternative for Douglas 2 3/4hp engines - but you need to ensure electrodes will not fould valves.  I have a pair of 'New old stock' D8 plugs as the on-bike spares. 

  I suspect as Champion was commonly sold in US, that earlier Champion pluges were predominantly this thread - but not entirely, see below in metric threads.

  - KLG:  FE75 14mm plug (1950s style plug?) 

  - Lodge:  Some Lodge threads were UNC, others were metric.  Three of the pink ceramic Lodge plugs I have in my collection were this 8 UNC thread - CANY plug (common 14mm plug), HL14S (pink ceramic 14mm plug - but with earlier seperate hex component for locking in cermaic and H14S with brass cooling fins fitted (this last plug was the one with the big knurled Lodge nut and cooling fins shown in many of the photographs - that we used as a template for 0895_5)

  - Wipac Pacey: F2.0 - blue ceramic 22mm plug

  - AC :  AC 78 22mm plug, made in the USA.  Note, in the accompanying photograph there is a second very similar plug to this, which is also 8 UNC - but has no marking whatsover.  I think this second plug may be another AC or possibly a Bosche make

  - Autolite: In the accmpanying photograph is a 'new old stock' Autolite A652.  Not a common plug - but I believe a 1960's-80's 14mm long reach plug 

- 4mm x 0.70mm Thread (0895_2 and 0895_5):  

    -  NGK: This looks to be the thread adopted by all modern NGK plugs - in case you want to fit a good quality, easily available, modern (14mm) plug  on your old motorcycle, but still use these knurled brass nuts for a period look.  NGK plugs tried included B6ES (common 14mm long reach, including fitted to many british bikes), B9HC and B77HC

  -  Item 0896_1 KLG Plug: Our 18mm KLG ML50 new plugs (Item 896_1) use this metric thread.  Note; as supplied these plugs come with the normal HT cap modern round nut - so if you want to use a knurled nut, they are with this thread

- Original KLG: KLG FE100 14mm plug, which is 'new old stock' and looks to be of 1950's-60's vintage.  Note: this plug looks very similar in appearance to the FE75 plug above, which is UNC - so it looks like KLG at this period used both thread types!

  - Champion:  I found at least one more modern Champion plug fitted with this metric 0.7mm Thread - Champion N62R (1970's-80's racing plug.  I would not be suprised to find more modern Champion plugs also fitted with this metric thread

- Lodge : This is probably the most difficult make of plug to identify thread for - as I found plugs of same 1930's - 1960's (pink ceramic) era with both metric and UNC thread type.  Those found with this 4mm x 0.7mm thread were - RL51 (the famous racing type plugs so favoured on Manx Norton's, 7R's, KTT's etc) / 2HLN / 3HLN

- 3 BA Thread (0895_3 and 0895_6):  

    -  KLG (very early?): I have read that 3 BA thread were fitted to a few spark plugs.  In my own collection I have only found one plug that uses this thread - but it is the very early KLG Brown Mica ceramic type - model number LK1 (the oldest plug in my collection).    It should be noted that a similar KLG plug to this one - the HS1 type was listed as original fitment for Douglas 2 3/4hp models (amd I would be interested in purchasing if you happen to have 2 of these in working order!)

- 4mm x 0.75mm Thread (0895_7):  

  Similar to the 3 BA thread, I have read that the 0.75mm pitch (4mm) thread was also sometimes used on spark plug HT nuts.  In my own collection I have only found one NGK plug (and an obscure one at that!) that uses this thread, but I have made a small quantity of Champion style nuts with this thread, just in case you want one!:

    -  NGK:  I have one older style NGK plug - an unusual C10M (see photo) plug which employs this less well known 0.75mm pitch thread.  It may also have been used on other early NGK or other makes of more modern plugs.  

- Other thread types not catered for:  I have one other pluge - an 18mm Lodge from the 20's-30's which has white porcelain and a larger 10 UNF fine thread.  I think  this plug is possibly from a motor car, and the top thread may be intended for a wire style HT top clip, not knurled nut.  I have not made nuts for this obscure plug - but if you know of a this or other threads (with some market!) I may consider making a small batch to htat thread (email our normal sales@racingvincent.co.uk).

Final point.  I am not intending to make any other brass spark plug parts in the near future, but if you believe there is a particular type missed or fitted to early Edwardian or Norton motorcycles - then let me know and we will consider making a batch.

Likewise - with older style spark plugs, we are able to supply a small quantity of the rare KLG 18mm long reach plug (similar to fitted to early Douglas motorcycles and possibly some early Norton engines) - but do not have any plans to supply others.  However, if anyone knows of good quality 18mm long reach plugs still available, we would be interested to hear, thanks 

This is the 'short tang' type gearbox kickstarter spring fitted to the 3 Speed Sturmey Archer CS type gearbox, and possibly other early Sturmey Archer gearbox's - both Norton and other marques, this most likely being for earlier, 1920's SV/OHV modelss - but please read all of this description listing - and that of Item 1108 before confirming this is the correct spring for your model - as this pattern is slightly different to the other Sturmey CS type spring we sell (Item 1108), and there were many variations of Sturmey Archer gearbox throughout the 1920's and into the early 1930's. 

Price is each.

We used a genuine original Sturmey Archer kickstart spring for the pattern for manufacturing this spring - but this particular spring was found in a box of Sturmey Archer gearbox parts I have owned for many years, obtained from someone who had owned many 1920s's/30's bikes - Norton's being prevelant, but I cannot guarantee this spring originated from a Norton CS gearbox.

However, the original spring did come from a Sturmey Archer CS type gearbox of the 1920's era - and looking at other photographs of CS type gearboxs - it seems most likely that the earlier CS type gearbox used a spring with a shorter tang - i.e. the straight part that came out from the spring coil, with a loop at the end, that was used to loop around the shaft of the kickstart lever of these models.

I have included a photograph of a very original 1925 Model 18 Norton, which was fitted with a CS type gearbox - and looks to employ this 'short tang' version spring (acknnowledgement to www.Bonhams.com - who provide excellent photographs of many original bikes of this era, and are well worth visiting if you are considering buying either a complete bike, or spare parts) - which indicates that this earlier Norton model may have used this gearbox kickstarter spring (Item 1064), rather than our other CS 'long tang' type gearbox spring - Item 1108, which I know was fitted to the later CS gearbox's, into the early 1930's.

This spring is unusual, in that it is has forward facing tang and loop, which fed through a hole in the kickstart spring cover (see accompanyning photos), and then looped behind the shaft of the kickstart lever.  

If you own a Norton model (or indeed any other similar aged marque that may have also fitted Sturmey Archer gearbox's in this period), then it is important you also look at our similar Item 1108, as we offer two different type of springs from this era, that although are very similar, have slightly different tang length's, and the spring ends are at different positions - so please check the accompanyning photographs for both listings before ordering - we try to show the exact differences between the two different types, so you can select which looks most correct for your particular gearbox.

When looking at the phtograph that shows the 'clock' position the tangs are positioned at for both springs - it should be remembered that it would be normal to pull the kickstart back (i.e. anticlockwise) slightly, so the kickstart is under slight pressure, even when at the top of its stroke - so take this into account when looking  at the spring end positions.

Both this spring (Item 1064) and the other CS spring (Item 1108) have a kickstart spring tang that protrudes outward from the gearbox approximately 20mm, meaning the kickstart lever is very close to the gearbox cover.  The later CRS gearbox spring (Item 1065) protrudes out much further, meaning the kickstart shaft protrudes further out from the gearbox end cover than the CS model.

6A final point - I am not an expert on early Sturmey Archer gearbox's (very few people are these days for obvious reasons!) - and have only pieced together the information shown here from looking at many photographs from different models, customers and friends who still have these - and looking at the few Sturmey Archer gearbox spares I own myself.  If you think you can provide more information - or own models with other types fitted - feel free to email us on sales@racingvincent.co.uk - we will be happy to update these listings with more information, or add other springs if patterns become available.expert 

The length the tang protrudes on this spring is approximately: 26mm (this being the straight section between bend and start of top loop)

The outer diameter of the spring is approximately: 47.5mm

The kickstarter tang protrudes out approximately: 20mm from the main coil spring

This is now an extremely difficult spring to find, and many original gearbox's are likely to be suffering with the original spring worn and tired - this new spring should help revitalise the kickstart lever returning!  It is slightly more expensive than later springs, as we have had to pay setup on a smaller size of batch than the later springs - hope this makes sense.

This is the 'long tang' type gearbox kickstarter spring fitted to the 3 Speed Sturmey Archer CS type gearbox - as fitted to most Norton SV and OHV models in the mid 1920's to approximately 1932.  We also sell a similar CS type spring with shorter tang (Item 1065), See listing detail for information on each type.

Price is each.

We used a genuine original Sturmey Archer (for Norton models) kickstart spring for the pattern for manufacturing these springs - so they are just as per the original spring.  This spring came from a CS gearbox fitted to a 1930 Norton OHV model, and the original spring even had pitting along its length - indicating it is a very old spring, and possibly the original spring fitted to that gearbox (very kindly lent to me by a customer who owned the bike).

This spring is unusual, in that it is has forward facing tang and loop, which fed through a hole in the kickstart spring cover (see accompanyning photos), and then looped behind the shaft of the kickstart lever.  

If you own a Norton model (or indeed any other similar aged marque that may have also fitted Sturmey Archer gearbox's in this period), then it is important you also look at our similar Item 1064, as we offer two different type of springs from this era, that although are very similar, have slightly different tang length's, and the spring ends are at different positions - so please check the accompanyning photographs for both listings before ordering - we try to show the exact differences between the two different types, so you can select which looks most correct for your particular gearbox.

It is difficult to be definitive about which year and which models used which particular spring - as there seemed to be many different Sturmey Archer gearbox's with minor variations through the 1920's (and Norton Spare Parts List did not seem to clearly identify one type from another) - but this type has a slightly longer tang than Item 1064 - and the pattern spring we used definitely came from a 1930 model - which indicates that this spring was probably more likely to be fitted to late 1920's-early 1930's Norton's using the CS gearbox, but it could be this spring type was also fitted on earlier models - but in parallel to the short tang type gearbox (Item 1064).

However, it is worth looking at the picture of gearbox shown for Item 1064 as a comparison - as this is taken from a 1925 Norton model, and that gearbox looks to have been fitted with the 'short' length tang kickstarter spring.  So, although not definitive - it may be possible that the earlier versions of the CS gearbox were fitted witht the short tang type (Item 1064), and later types of this gearbox were fitted with this spring (Item 1108).  To support this - you will notice that the later (i.e. 1930) type gearbox shown here also had a pressed steel kickstart lever retaining clip bolted to the gearbox cover just above the kickstart shaft, which the mid-1920's version did not have - which may explain why the tang lengths are different, to avoid fouling this clip.

When looking at the phtograph that shows the 'clock' position the tangs are positioned at for both springs - it should be remembered that it would be normal to pull the kickstart back (i.e. anticlockwise) slightly, so the kickstart is under slight pressure, even when at the top of its stroke - so take this into account when looking  at the spring end positions.

Both this spring (Item 1108) and the other CS spring (Item 1064) have a kickstart spring tang that protrudes outward from the gearbox approximately 20mm, meaning the kickstart lever is very close to the gearbox cover.  The later CRS gearbox spring (Item 1065) protrudes out much further, meaning the kickstart shaft protrudes further out from the gearbox end cover than the CS model.

A final point - I am not an expert on early Sturmey Archer gearbox's (very few people are these days for obvious reasons!) - and have only pieced together the information shown here from looking at many photographs from different models, customers and friends who still have these - and looking at the few Sturmey Archer gearbox spares I own myself.  If you think you can provide more information - or own models with other types fitted - feel free to email us on sales@racingvincent.co.uk - we will be happy to update these listings with more information, or add other springs if patterns become available.expert 

The length the tang protrudes on this spring is approximately: 44mm (this being the straight section between bend and start of top loop)

The outer diameter of the spring is approximately: 47.5mm

The kickstarter tang protrudes out approximately: 20mm from the main coil spring

This is now an extremely difficult spring to find, and many original gearbox's are likely to be suffering with the original spring worn and tired - this new spring should help revitalise the kickstart lever returning!  It is slightly more expensive than later springs, as we have had to pay setup on a smaller size of batch than the later springs - hope this makes sense.

This is the gearbox kickstarter spring fitted to the 3 Speed Sturmey Archer models that were fitted to Walter Moore Norton CS1 and ES2 models in the late 1920's, through to the first Arthur Carroll engines and other models, to approximately 1932.  It has a long tang that protruded out and wrapped around the kickstart. 

Price is each.

We used a genuine original Sturmey Archer (for Norton models) kickstart spring for the pattern for manufacturing these springs - so they are as per originals.

This spring is unusual, in that it is has forward facing tang and loop, which fed through a hole in the kickstart spring cover (see accompanyning photos), and then looped behind the shaft of the kickstart lever.  The length that this tang protruded is important, as other Sturmey Archer gearbox's had a similar spring - but with a shorter length protruding (see also Item 1064).

The length the tang protrudes on this spring is approximately: 44mm

The outer diameter of the spring is approximately: 47.5mm

It is difficult to be definitive about exactly which Sturmey Archer Gearbox's and models this spring was fitted to - but it is certainly of the type that was fitted to the sporting Norton Models from 1927 through to approximately 1932 - as it is listed in the 1927/28 Norton Spare Parts catalog for Walter Moore type CS1 and ES2 models.  At this point the spring was shown as part number 4585.  I cannot be entirely sure - but I believe the gearbox was known as the CRS type gearbox (please email me if you think I have got this wrong!).

It was then shown again in the 1930-31 Spare Parts Catalog, by which time this gearbox was now being fitted to the newly introduced Arthur Carroll type SOHC CS1 engine, as well as the ES2 models.  By this time the part number had changed to 5X44. See accompanyning photos for exerts of both these catalog pictures.

The following year (i.e. 1932) the Sturmey Archer 4 speed gearbox was introduced for the SOHC Mod30/40 models with a different kickstarter spring type (see Item 1066) - but the 3 speed gearbox was still listed for the CS1 models - so although I cannot be sure if the spring design changed, the 1932 3 speed may have continued to use this spring type - and it may have also been used on other models at that point in time (again, please email if you have a 3 speed of 1932-34 design and can confirm this, thx).

This spring may have also been fitted to other manufacturers models fitted with Sturmey Archer 3 speed gearbox's from mid 1920's to early 1930's - if unsure, the important dimensions to check are shown above - the distance the tang protrudes to reach the kickstarter shaft, and the width of the spring (and again - I would be happy to update this listing if anyone knows of other models using it).

As a final point - as at time of the writing this listing (Jan 2022) - I am in the process of having a small batch of the spring covers manufactured - as shown in the centre of the photo with the springs and covers together.  These were tin covers (although we may need to machine from solid), with a hole for the forward facing tang to protrude.  Email us on sales@racingvincent.co.uk if you wish to reserve one.

This is now an extremely difficult spring to find, and many original gearbox's are likely to be suffering with the original spring worn and tired - this new spring should help revitalise the kickstart lever returning! 

This is the gearbox kickstarter spring fitted to the 4 Speed Sturmey Archer models from approximately 1932-34, visually similar to the Norton gearbox spring that followed it, this spring has a wider diameter.  It is identifiable from earler Sturmey gearboxs in having one tang facing inwards, and the other facing backwards .

Price is each.

We used a genuine 'New Old Stock' Sturmey Archer (for Norton models) kickstart spring for the pattern for manufacturing these springs - so they are as per originals.

It is difficult to be definitive about exactly which models (and when) were fitted with this type of kickstart spring - but reading through Norton literature of the period - this spring seems to have been fitted mainly to the Four Speed (CSR) Sturmey Archer gearbox types.  The 4 speed gearbox looks to have be first supplied on SOHC (Mod 30 and 40) models on their introduction in 1932.  In 1933 the 4 speed was also offered for the SOHC CS!/CSJ.  Then for 1934 it was shown as available for all models - albeit with a slightly different positive stop mechanism on OHV/SV models.

In late 1934 - early 1935 the Sturmey Archer gearbox was replaced with Norton's own similar design, based on the earlier Sturmey design but with many smaller design differences - including the kickstarter spring, which was easily identifiable by having a smaller diameter coil section. 

For identification if you are not sure if this is the correct spring for your gearbox - It has an outer diameter of 47.5mm and a depth of coils of approximately 21mm

This is now an extremely difficult spring to find, and many original gearbox's are likely to be suffering with the original spring worn and tired - this new spring should help revitalise the kickstart lever returning! 

This is the spring that was fitted in the mid/late 1920's up to approximately 1930-31, for those models that were fitted with the large right side mounted rear brake drum (which I believe were supplied by Royal Enfield originally), and then used a one piece crossover shaft attached to the brake pedal - so a left foot brake pedal could be used. See the attached pictures, taken from the 1929 CS1/ES2 Norton Spare Parts List - which show the brake pedal and associated parts for the rear brake mechanism - and shows clearly the spring offered here - Original Part Number 4504.

As shown in the catalog - it was standard fitment on the Norton 3 - stay frame up until Norton introduced their own brake drums and mechanism in approximately 1931/32 on the left side of the bike- at which time they changed over to what become the standard brake pedal with return spring mounted on the brake plate.  Therefore the later 3 stay frames with combined rear hub/sprocket should not need this type of spring.

Other models (i.e. OHV and possibly some SV) with two stay rear frame, but also employing the brake hub on the Timing side of the bike, and a crossover shaft/brake pedal will also have employed this spring - and our original Norton pattern shown in the second photograph - which was used as the pattern for replicating this spring came from a 1930/31 Model 18.  There is also a picture of a restored 1930 Model 18, so you can see the type of brake mechanism that fitted this type of spring.

The spring fits onto the crossoveer shaft of the brake pedal and loops onto the frame tube, it being fitted on the brake lever side of the crossover shaft.

This is now an extremely rare spring to find in its original form and ours are copied directly from an original Norton pattern by our specialist UK spring manufacturer.  Not as cheap as some springs - as setup costs are high for a relatively small batch quantity . . . but hopefully if you have an original with corrosion or broken . .. at least you know this one is correct! 

nd brake pedal.  This spring fits behind the brake pedal and has a loop that acts on the frame tube.  This spring is copied from an original Norton pattern - see listing for more detail.  Price is Each 

Price is each.

We used a genuine original Sturmey Archer (for Norton models) kickstart spring for the pattern for manufacturing these springs - so they are as per originals.

This spring is unusual, in that it is has forward facing tang and loop, which fed through a hole in the kickstart spring cover (see accompanyning photos), and then looped behind the shaft of the kickstart lever.  The length that this tang protruded is important, as other Sturmey Archer gearbox's had a similar spring - but with a shorter length protruding (see also Item 1064).

The length the tang protrudes on this spring is approximately: 44mm

The outer diameter of the spring is approximately: 47.5mm

It is difficult to be definitive about exactly which Sturmey Archer Gearbox's and models this spring was fitted to - but it is certainly of the type that was fitted to the sporting Norton Models from 1927 through to approximately 1932 - as it is listed in the 1927/28 Norton Spare Parts catalog for Walter Moore type CS1 and ES2 models.  At this point the spring was shown as part number 4585.  I cannot be entirely sure - but I believe the gearbox was known as the CRS type gearbox (please email me if you think I have got this wrong!).

It was then shown again in the 1930-31 Spare Parts Catalog, by which time this gearbox was now being fitted to the newly introduced Arthur Carroll type SOHC CS1 engine, as well as the ES2 models.  By this time the part number had changed to 5X44. See accompanyning photos for exerts of both these catalog pictures.

The following year (i.e. 1932) the Sturmey Archer 4 speed gearbox was introduced for the SOHC Mod30/40 models with a different kickstarter spring type (see Item 1066) - but the 3 speed gearbox was still listed for the CS1 models - so although I cannot be sure if the spring design changed, the 1932 3 speed may have continued to use this spring type - and it may have also been used on other models at that point in time (again, please email if you have a 3 speed of 1932-34 design and can confirm this, thx).

This spring may have also been fitted to other manufacturers models fitted with Sturmey Archer 3 speed gearbox's from mid 1920's to early 1930's - if unsure, the important dimensions to check are shown above - the distance the tang protrudes to reach the kickstarter shaft, and the width of the spring (and again - I would be happy to update this listing if anyone knows of other models using it).

As a final point - as at time of the writing this listing (Jan 2022) - I am in the process of having a small batch of the spring covers manufactured - as shown in the centre of the photo with the springs and covers together.  These were tin covers (although we may need to machine from solid), with a hole for the forward facing tang to protrude.  Email us on sales@racingvincent.co.uk if you wish to reserve one.

This is now an extremely difficult spring to find, and many original gearbox's are likely to be suffering with the original spring worn and tired - this new spring should help revitalise the kickstart lever returning! 

This is a 'Variable' Listing, showing various types of Norton sump plugs - as were fitted to most Norton models from the 1920's through to the 1950's, both engine and gearbox, and also some additional 'Racing' type, either drilled for Lockwire and even a couple 'Wasted' for weight saving.  All are modelled on original Norton sump plugs - with all major dimensions replicated .  Price is Each - but also includes the sump plug washer.  We also sell the various washer types serperately.  See the table below for details and fitting for each sump plug type we offer

All our sump plugs are CNC manufactured by ourselves to original dimensions, using original patterns as examples - and trial fitted to original crankcase and gearbox castings of various single cylinder models.  All 1/4" BSP sump plugs (i.e. 1011_1 to 1011_10) are manufactured in brass, just as original Norton sump plugs were - then satin nickel plated (also the most common original finish).  As well as replicating the original different designs manufactured over a 30 year period - they also look extremely pretty.  For most of the brass type sump plugs - we have also held back a few in bare brass - which was also an original Norton finish - but these are limited.

By default for items 1101_1 to 1101_10 - we will send a satin nickel plated sump plug - state when placing online order in the comment section if you require a brass version instead (if available)

Note also that many OHV and SV oil tanks were also fitted with 1/4" BSP Drain/Sump Plugs - often listed as part number E3336, where the head shape was often similar to our 1101_1 or 1102_2 - the second of these being a lockwired version, which is a useful addition on any oil tank.  Ensure your oil tank sump plug thread is actually 1/4" BSP before fitting though, but if so, any of our brass 1/4" BSP plugs should fit (note - many SOHC oil tanks did not have drain plugs fitted) 

Also the Norton 'Oilbath' Chaincase also used an E3336 sump plug - I have seen both plain head and slotted variety fitted to the chaincase in the past.  And of course a lockwired version is very useful if you are intending taking your roadbike on a Track parade.

Which Plug: 1/4" BSP, 1/8" BSP or another thread type?? - Different sump plug fittings:  It is worth noting that the first 10 sump plugs are all 1/4"BSP threads, which was by the far the most common fitting for gearbox and oil tanks and for engine sump plugs up to 1948.  However many Post 1948 Norton single cylinder (and other model) crankcases were instead fitted with a smaller thread sump plug thereafter - which was normally 1/8"BSP.  Most of these engines are identifiable from earlier engines, because the sump plug was mounted under the crankcase, rather than at the side, and there was often an additional casting ramp in front of the hole, to stop the sump plug being pulled out if the bike was 'grounded'. 

We have replicated this later Post 48 Sump plug as well - see items 1101_11 and 1101_12 (locwired version).  An original 1/8" Norton sump plug was again used as a template, which we have CNC replicated exactly - other than ours are manufactured in stainless steel, rather than the original plated steel material that original 1/8"BSP were made in - so ours will not rust. 

It is important that you check your fitting before ordering though - particularly if you have a Post 48 model - because the original 1/8"BSP plug used a very fine thread, and the sump alloy was not very thick . . . it is very common to find that the crankcase may have stripped its thread in the past and been fitted with a different - slightly larger thread.  I have found the most common 'larger' thread is 7/16" BSF (and I have a couple of crankcasses in my own collection since the 1960's that have had this done) . . . so because of this we have also manufactured a Post 48 sump plug - but with 7/16" BSF thread - Item 1101_13.  I have talked to other highly experienced Norton engine builders and they also confirm stripped threads on later engines is a common occurrence.  Please satisfy yourself which thread you require before ordering

Types Available are as Follows:

Note: I have desctribed below the different variations, and wherever possible - the most common fitment of each . . . to the best of my knowledge from having stripped various original engine and gearbox's over the last 40 years, as well as talking to friends and customers where necessary.  However, providing thread and fitment is correct - you may find these plugs styles also fitted to other models, or different to below:

Background and Fitting Notes:

These are CNC manufactured by ourselves, but using original Norton sump plugs as a pattern - which we have copied exactly - including chamfers, grooves (most of these sump plugs have a specific type of groove behind the thread, which I assume was to let the red fibre washer to 'mush out' slightly and give more effective sealing) - and of course, the correct Norton head profiles.  We also linish (with fibre linishers) the head after manufacture to remove burrs, and then finally, every nut is ran down a thread gauge, to ensure the thread is deburred.  We have also manufactured additional varieties with cross-drilled holes for lockwiring - for track and competition use, and also some 'lightened' types with a very pretty drilled head.

Norton sump plugs for Norton singles were manufactured in their 1000's over a 50 year period - and as always there were slight variations and tolerances by batch - but we have compared multiple sump plugs and have tried to adopt 'std' tolerances wherever possible.  However, when fitting, try and ensure the thread fitting you have selected is correct for your model - always grease the thread first, and if not sure - play safe and confirm thread in casing first.

Note - Each of the sump plugs (between 1101_1 and 1101_12) comes supplied with a BSP Dowty sealing washer.  These are much easier to fit than the traditional Red Fibre Washer (which must be a very tight fit onto Norton sump plugs - and are difficult to fit - if they go on easy, they will 'wobble' when they get to the grooved area that all these sump plugs have). 

Dowty sealing washers are a more modern design - consisting of a steel outer with sealing nitrile inner - and are used in most modern fittings for sealing plugs.

We also sell these 1/4" or 1/8" BSP washers seperately (1101_14 and 1101_15 respectively), as ideally they should be replaced every time an oil change is performed.

We can also supply the traditional Red Fibre washers (Item 0091) if youj wish to use the traditional style washer - particularly on the Lipped type washers - but note these are normally a bit more difficult to fit.

Final point - if you have a different type of sump plug to the type shown here, and think it is original (i.e. early 1920's etc) - then feel free to email us and we may consider manufacturing a batch

These Red Fibre Washers are a smaller diameter than 'normal' 1/4" BSP washers - but then pre-threaded by us - so they are a good fit on those Norton fittings that used 1/4" BSP thread, but have a groove behind the thread - e.g. Norton pre-48 Oil Sump Plugs and some breather union fittings. 

This listing is for a bag of 5 washers

Background:

For anyone that is familiar with Norton single cylinder models (and earlier twins) - they will know that it was not unusual to make some oil and petrol fittings with a 1/4"BSP thread, but with a groove machined between the thread and the rear face of hex spanner head.  Added this, often the hex was not very wide (what you will see referred to as 'Reduced Hex' by us throughout this catalog for Norton specific fastenings), so there was little hex face for the fibre washers to seal against.  

The two best examples of this are the Pre-48 style 1/4" BSP Norton Sump Plug (in all its guises) and some breather unions (see photographs - some Unions had grooves, while others did not).

Therefore, if you try and fit a 'normal' 1/4" BSP red fibre washer to this type of sump plug or union - it will go on easily, but when it gets to the groove - it will wobble around.  Then, when the sump plug or union it tightened, the wobbling washer will normally move over to one side - and there will be a very good chance it will leak, or just crush and break up when tightened.

In the past we have sold this size of 'tighter fit' washer - telling customers they will need to be prepared to use some force to wind the washer past the thread - but franky - the best quality red fibre washers are very hard, and extremely difficult to wind onto the thread!

Therefore, as part of work we did in early 2022 to replicate most Norton sump plugs, we also looked at how we could make this easier - and eventually have come up with a jig process to pre-thread these washers with a 1/4" BSP thread - as shown here.

So, although not very thick - if you look closely at these washers you will see they have an intenal thread cut into them (see also the taper tap we use for this process) . . . and that means that, although still tight, they can now be carefully screwed onto a 1/4" BSP thread by hand - but will a 'Size' fit on the groove behind the thread - therefore giving a much better chance for the washer to seal properly!

If trying to tap a single washer, it will normally just crush the washer, but with experimentation and a jig, we have come up with a process to manualy thread these washers, so they will just 'screw on' by hand.

This may sound like a simple issue . . . but actually most proprietary 1/4" BSP washers are actually quite loose on a 1/4" BSP thread (see our Item 1111 for 1/4" BSP washers that are a good fit!), but good quality red fibre washers are normally much harder than cheap washers - the washers we use are supplied by one of the best (and most expensive!) washer suppliers - and therefore require this pre-threading process . .. trying to screw it on without doing this is almost impossible.

Sorry these washers are so expensive for what looks such a simple and cheap looking thing - but hopefully you will understand that the jig and time it takes to manually thread them is what results in the extra cost - but definitely worth using if you prefer the original type Red Fibre washerer, rather than modern Dowty (nitrile/steel) washers.

We also sell these as a pair (Item 0941), or close fitting 'normal' 1/4" BSP washers (Item 1111) for those unions and tap fittings which dont have a groove behind the thread 

These Red Fibre Washers are a smaller diameter than 'normal' 1/4" BSP washers - but then pre-threaded by us - so they are a good fit on those Norton fittings that used 1/4" BSP thread, but have a groove behind the thread - e.g. Norton pre-48 Oil Sump Plugs and some breather union fittings. 

This listing is for a pair of washers (i.e. x2)

Background:

For anyone that is familiar with Norton single cylinder models (and earlier twins) - they will know that it was not unusual to make some oil and petrol fittings with a 1/4"BSP thread, but with a groove machined between the thread and the rear face of hex spanner head.  Added this, often the hex was not very wide (what you will see referred to as 'Reduced Hex' by us throughout this catalog for Norton specific fastenings), so there was little hex face for the fibre washers to seal against.  

The two best examples of this are the Pre-48 style 1/4" BSP Norton Sump Plug (in all its guises) and some breather unions (see photographs - some Unions had grooves, while others did not).

Therefore, if you try and fit a 'normal' 1/4" BSP red fibre washer to this type of sump plug or union - it will go on easily, but when it gets to the groove - it will wobble around.  Then, when the sump plug or union it tightened, the wobbling washer will normally move over to one side - and there will be a very good chance it will leak, or just crush and break up when tightened.

In the past we have sold this size of 'tighter fit' washer - telling customers they will need to be prepared to use some force to wind the washer past the thread - but franky - the best quality red fibre washers are very hard, and extremely difficult to wind onto the thread!

Therefore, as part of work we did in early 2022 to replicate most Norton sump plugs, we also looked at how we could make this easier - and eventually have come up with a jig process to pre-thread these washers with a 1/4" BSP thread - as shown here.

So, although not very thick - if you look closely at these washers you will see they have an intenal thread cut into them (see also the taper tap we use for this process) . . . and that means that, although still tight, they can now be carefully screwed onto a 1/4" BSP thread by hand - but will be a 'Size' fit on the groove behind the thread - therefore giving a much better chance for the washer to seal properly!

If trying to tap a single washer, it will normally just crush the washer, but with experimentation and a jig, we have come up with a process to manualy thread these washers, so they will just 'screw on' by hand.

This may sound like a simple issue . . . but actually most proprietary 1/4" BSP washers are actually quite loose on a 1/4" BSP thread (see our Item 1111 for 1/4" BSP washers that are a good fit!), but good quality red fibre washers are normally much harder than cheap washers - the washers we use are supplied by one of the best (and most expensive!) washer suppliers - and therefore require this pre-threading process . .. trying to screw it on without doing this is almost impossible.

Sorry these washers are so expensive for what looks such a simple and cheap looking thing - but hopefully you will understand that the jig and time it takes to manually thread them is what results in the extra cost - but definitely worth using if you prefer the original type Red Fibre washerer, rather than modern Dowty (nitrile/steel) washers.

We also sell these as a bag of 5 (Item 0249), or close fitting 'normal' 1/4" BSP washers (Item 1111) for those unions and tap fittings which dont have a groove behind the thread 

These Red Fibre Washers are a nice close fit on 1/4" BSP threads and are useful for many Norton fittings - such as those breather unions and petrol taps that have a 1/4" BSP thread that comes up close to the hex or shoulder.

We bring thsese washers in specially for this purpose.

Price is per pair.

Although it may sound obvious - good close fitting 1/4" BSP red fibre washers are actually quite difficult to find these days - most washers advertised as 1/4" BSP are actually a slightly sloppy fit on that thread - resulting in only a limited amount of material actually sealing when the washer is fitted (we know this - because we have looked at those supplied by many manufacturers over the years!

These washers are a good close fit to the thread and work best where there is no groove behind the thread - allowing the washer to be as effective as possible, i.e. the non shouldered breather unions (our Item 0248 - as shown in the listing pictures) often fitted to Norton single models.

These are good for things such as Norton single models - crankcase One Ways Valves and those breather unions which do not have a groove behind the the thread, and of course things such as 1/4" BSP fuel taps.

Note: we also sell special 'Pre-threaded' tight fit 1/4"BSP fibre washers for those Nortin fittings that do have a groove behind the thread - i.e. orgiinal pre-48 Sump Plugs and some unions - see Item 0249 and 0941

These Red Fibre Washers are a smaller diameter than 'normal' 1/4" BSP washers - but then pre-threaded by us - so they are a good fit on those Norton fittings that used 1/4" BSP thread, but have a groove behind the thread - e.g. Norton pre-48 Oil Sump Plugs and some breather union fittings. 

This listing is for a bag of 5 washers

Background:

For anyone that is familiar with Norton single cylinder models (and earlier twins) - they will know that it was not unusual to make some oil and petrol fittings with a 1/4"BSP thread, but with a groove machined between the thread and the rear face of hex spanner head.  Added this, often the hex was not very wide (what you will see referred to as 'Reduced Hex' by us throughout this catalog for Norton specific fastenings), so there was little hex face for the fibre washers to seal against.  

The two best examples of this are the Pre-48 style 1/4" BSP Norton Sump Plug (in all its guises) and some breather unions (see photographs - some Unions had grooves, while others did not).

Therefore, if you try and fit a 'normal' 1/4" BSP red fibre washer to this type of sump plug or union - it will go on easily, but when it gets to the groove - it will wobble around.  Then, when the sump plug or union it tightened, the wobbling washer will normally move over to one side - and there will be a very good chance it will leak, or just crush and break up when tightened.

In the past we have sold this size of 'tighter fit' washer - telling customers they will need to be prepared to use some force to wind the washer past the thread - but franky - the best quality red fibre washers are very hard, and extremely difficult to wind onto the thread!

Therefore, as part of work we did in early 2022 to replicate most Norton sump plugs, we also looked at how we could make this easier - and eventually have come up with a jig process to pre-thread these washers with a 1/4" BSP thread - as shown here.

So, although not very thick - if you look closely at these washers you will see they have an intenal thread cut into them (see also the taper tap we use for this process) . . . and that means that, although still tight, they can now be carefully screwed onto a 1/4" BSP thread by hand - but will a 'Size' fit on the groove behind the thread - therefore giving a much better chance for the washer to seal properly!

If trying to tap a single washer, it will normally just crush the washer, but with experimentation and a jig, we have come up with a process to manualy thread these washers, so they will just 'screw on' by hand.

This may sound like a simple issue . . . but actually most proprietary 1/4" BSP washers are actually quite loose on a 1/4" BSP thread (see our Item 1111 for 1/4" BSP washers that are a good fit!), but good quality red fibre washers are normally much harder than cheap washers - the washers we use are supplied by one of the best (and most expensive!) washer suppliers - and therefore require this pre-threading process . .. trying to screw it on without doing this is almost impossible.

Sorry these washers are so expensive for what looks such a simple and cheap looking thing - but hopefully you will understand that the jig and time it takes to manually thread them is what results in the extra cost - but definitely worth using if you prefer the original type Red Fibre washerer, rather than modern Dowty (nitrile/steel) washers.

We also sell these as a pair (Item 0941), or close fitting 'normal' 1/4" BSP washers (Item 1111) for those unions and tap fittings which dont have a groove behind the thread