1937 Royal Enfield 1140cc sidevalve model KX                                                                            December 2016

Museum bike

Whilst restoring the Enfield Bullet, I went to a little motorcycle museum that was housed in the stable block of Nostell Priory near Wakefield. This was mostly the collection of the late Harry Fenby from Hull, but with a few additional bikes owned by others. There I came across my first ever v twin Royal Enfield - and I was smitten! The bike was behind the bars of the horse cubicle, and a bit difficult to photograph (I also had a fairly crappy camera at the time). Unusually, this bike had been ridden by a disabled guy, and the hand change lever had been moved to the far side of the tank (the rod can be seen coming up from the gearbox and disappearing under the petrol tank between the cylinders). The bike had also been modified at the front end, and a hydraulic/coil spring shock absorber unit had replaced the original girder spring.

In 1977 I put an advert in Motorcycle News, "looking for KX information, parts, anything up to and including a rusty wreck".


Advert reponse                                            December 2016

Rusty wreck

Imagine my surprise when a chap rang up with the words "I've got just what you're looking for" (what's that?) "a rusty wreck"! It was only 30 miles away, so I went for a look.....

History                                                          December 2016

The bike in a former life

The British Ministry of Transport test for vehicles (MOT test) was introduced in 1960. The current owner took the bike with sidecar along for it's 1st ever test. It failed dismally - play in the forks, play in the wheel bearings, rubbish brakes, etc, etc. The guy brought it home, stood it in the garden. A neighbour offered him £10 for the sidecar. The sidecar was detached, and sold, the bike was laid down with a sheet over it. I came along 17 years later and he had freshly wrenched it out of the ground using an engine hoist. The little bit of exhaust pipe that was left was like tissue paper, all the steel had rotted away and left the chrome and nickel plate! The petrol tank was also originally chrome plated, there was about 6 square inches left - also similar to tissue paper!

Proud owner of a pile of scrap                    February 2017

KX engine after removal - in a very sad state

Well, I invested a whole £10 of hard earned cash to bring the rusty wreck home in the back of my Dad's Transit van. When I opened the van doors to show it off, he couldn't believe his eyes. In his opinion, the previous owner should have paid me £10 to take it away! As I said earlier 'beauty is in the eye of the beholder' (but not my father's eye). As a bit of perspective, an engine in similar condition was spotted at Beaulieu in September 2015. The asking price was £4500 - I would be surprised if it sold!

The bike was very badly rusted, most bolts had to be chiselled off (no access to oxy acetylene), and the photo shows the engine shortly after removal from the frame. The cylinder barrel and head fins have all but corroded away.

More vintage and veteran motorcycles to come.

1140 Oil system                                                  March 2017

1140 oil circulation diagram.

The dry sump recirculating oil system first used on the 1912 2 3/4 v twin racer got a bit more complicated for the next v twin to use a similar system.

The words are as follows:

The main supply of oil is carried in an oil tank A formed in the crankcase casting. (Note that this is not the sump, nor is oil carried in the sump which is kept dry). This tank has a capacity of over seven pints and should always be kept well filled.

The oil is sucked by the 2 feed pumps B and C (at the rear end of the timing cover) through a filter D. Pump B delivers oil to the big end from which it is splashed over the cylinders and pistons and is led by special channels to the main bearings. Pump C (which is smaller than B) provides an additional supply of oil to the front cylinder, which would otherwise receive less than the rear one. Surplus oil collects in the sumps E, E, at the bottom of the case, from which it is drawn by the first return pump F (which has a capacity greater than B and C together) through a second filter G, and is delivered to the timing case. The second return pump H (equal in size to F) draws the oil from a point at a high level in the timing case and returns it to the main oil tank A.

Lucas equipment for KXs                                     May 2017

Extract from Lucas Master catalogue

An extract from the Lucas Master Catalogue with all the original Lucas equipment fitted to the 1936-39 Ks and KXs (good luck with finding any of it these days).

For new KX owners                                               Oct 2017

As I've had my KX since 1977, I've gathered quite a bit of information together for '37-'39 1140cc K and KXs. I'm not going to put it all up here, on account of the potential for shady characters to try and make money out of something freely offered.

First up, there is a website for K/KX owners, but it is only available to owners (sensitive databases). You have to email the admin team to gain access: http://www.royal-enfield-1140.com

I will list below the stuff I have, so if you want/need a scanned copy, use the contact me page (including your engine/frame numbers so I can be reasonably confident you are a genuine owner) and I'll get something back to you.

Royal Enfield catalogues 1937, 1938, 1939

Royal Enfield sidecar catalogue 1937

K, KX parts list

K, KX instruction book

Series of restoration articles (3) originally featured in Motor Cycling in 1953

Roadtest of a 1939 model

Large scale drawing of 55 degree cam ring with all necessary info/dimensions for remanufacture.

Scale drawing of Amal handlebar twist dip and horn bakelite controls (Enfield actually used the Bowden version of these, but I did the drawing before I found out the differences). The Bowden version has a much finer serration to the bakelite, consequently most of them are pretty smooth these days! The Amal version retains it's "grippy" quality a bit better.

2 Lucas wiring diagrams to suit panel in tank and instruments in headlight.

That's all I can think of for the moment, if I find any more, I'll keep adding.



Fairly self explanatory, but in case you are in doubt, catalogue extract for 1937 K, KX. Note the pressed steel front forks. If you wanted tubular fork blades you had to wait until 1938 - not even offered as an option in '37.

Silencers (mufflers)                                              Oct 2017

1938/9 Enfield silencer

About 15-20 years back, I came across an original Enfield silencer as shown above (only fitted to the '37 bikes). It had seen better days, but the shape was there, and all the internals. I ground out the seams, and had Terry make a new "can" with all the original internals refitted. This silencer was first used in 1935 (I've got an article somewhere, I'll try and find it), and was claimed to be particularly efficient at silencing (but probably also good at performance sapping).

More recently, I came across this 1938/39 Enfield silencer on the dreaded ebay. Identifiable by the fishtail, and the oval body section, it is damaged at the front, but again completely original. No plans for it at the moment, but it could be re-skinned like the earlier version.

1936 range announced in September 1935. Last paragraph describes new silencer. Sketch to follow.

Internal composition of silencer, same as fitted to 1937 K, KX. Also introduction of pressed steel forks to some models, also to run on to '37 K, KX.

A "dry" build                                                           Nov 2017

Back in 2003, I got as far as this before dismantling and stuffing it back into numerous boxes.

Do you want more?

If you want to continue the story.........