Royal Enfield Diesel Motorcycles

The Royal Enfield motorcycle is ideal to be converted or customised to run on diesel because of the seperate gearbox. They are by far the most popular motorbikes at our Rallies too. Home.

Motorearth Royal Enfield Conversion.

A diesel motorcycle conversion kit starting from $2250.

Dan Borkowski's Diesel Enfield

My names Dan and I'm a long time lurker on the forum here. I really like motorcycle touring and figured that economy wise my current mount SR500 had to me a short range. I like old bikes then I found out about Indian Enfields. They have all I'm after: 350 or 500 single right side shift 4spd and ok mileage. After more surfing the net I discovered people had been fitting Diesel engines into 'em and getting extremely good mileage. I know a Diesel powered Enfield is nothing new but here's another one to add to the list.

Dan got some help from his brother building this bike.


It took a few months to build and was the project was plenty of fun. My bro helped with all of the welding as he's pretty good at it and I made all the other bits, cables etc. Engine is a Yanmar L100V. I've only got about 70kmls on Diesel so plenty of testing and long distance riding up ahead. At the moment it rides very well, much more enjoyable than in previous 350 form. For me there is not much difference performance wise between the 350 petrol and this. From what I read I was expecting it to be really slow especially up hills. Well I tell ya I was in for a surprise. For 10 horses it moves well up 15% grades. Very pleased!

Colin Clarke's 'Ruggerfield'.

This is the Royal Enfield Bullet converted by Colin Clarke in the 1990's. Using all his skills as a machinist he created a primary cover, milled blocks and fabricated brackets to hold a Ruggerini MD 191 850cc twin securely in place on this Enfield Bullet. I bought this bike at auction after hearing about it on the grapevine. See here or the story of how I won this bike at that auction.

Colin Clarke's creation. A bike that was fondly known as 'his baby'.


Diesel Powered Royal Enfields are now a reality at Price Part Motorcycles.

Diesel Engine powered Royal Enfield motorcycles are now here, powered by the Yanmar clone engine of 406cc. They now come with electric start, choice of front brakes, either the new disc brake or the classic twin leading shoe drum brake.
These are carefully rebuilt, the frames are powder coated gloss black, all small fitting parts, ie swinging arm, centre stand, foot rest pedals rear mudguard stays are also powder coated gloss black.
The wiring looms are all replaced with new genuine Royal Enfield looms, all switches are either OE supplier or factory original.
Wheels all have new hubs with stainless steel spokes and wheel rims fitted.
A choice of tyres is available, but standard is the classic Avon Speedmaster Mk2 tyres, size 3.25 x 19 front and 3.50 x 19 rear.
Other tyres can be fitted as etxra.
The mudguards, diesel tank, and tool boxes are all painted gloss black.
The dual seat is fitted as standard but single sprung seats are an option.
Prices for these start at £2950.00 for kick start. £3250.00 for electric start
All come with 12 months road tax and MOT where applicable

Beckedorf Royal Enfield Diesel Motorcycles

If you fancy a Royal Enfield with a 440cc Italian 15LD Lombardini engine look no further than The Beckedorf creation.

A Royal Enfield with an Italian Lombardini Engine.

The Centaurus 850cc Diesel Motorcycle

I had the pleasure of seeing one of the very first Centaurus Diesel Bikes at the 2003 Hamm Rally and can say they are a very nice looking and sounding bike. The Ruggerini 850cc engine with it's distinctive cylinders, fits very well into the Royal Enfield frame. For more information on this machine check out these links: IWAN Motorcycles, It seems the engine used on this particular bike was a bad design by Ruggerini. Both pistons going up and down together caused too much vibration.. Other models such as the MD191 are more suited as they are more traditional in design. One piston up whilst one piston is down.

The Centaurus. Available for under 7000 euros. Or was until prodution ended due to frame breaks.

Royal Enfield Ruggerini Diesel Motorcycle

Unlike the new Centaurus this is an older Bike which seems to have been a private conversion.

The Charnwood Royal Enfield 350cc Hatz

Enter the HATZ!!! Again we see the trusty Royal Enfield Bullet, this time fitted with a German made 350cc direct injection HATZ 1B30 Diesel engine. With 1:22 compression, electric start and good cold start performance this bike is just the thing if you aim to travel on the cheap with fuel consumption at 170 m.p.g. The engine produces 9 b.h.p. and is governed to around 3800rpm.

New bikes retail at £4250 from CHARNWOOD CLASSIC RESTORATIONS. They'll even fit an engine in your old Bullet for around £1999. Can't be bad. See below for more contact info.

This bike is no longer available. But you may be able to purchase a kit from Charnwood that uses the bigger 462cc engine. Essentially a Sommer Hatz bike.

TEL 01530 832634 FAX 01530 832357

The Horvath Diesel Motorcycle

Apparently Classic Corner Horvath builds Acme Diesel Engines into Royal Enfield Frames. Go here for more information.


Classic Corner Horvath looking very like a triumph?

RUGGFIELD 850cc Diesel Motorcycle

The guys involved with this project sent me their website and I and happy to put it up here for all to see.

The web site for this conversion kit is no longer active.

Sommer Royal Enfield 462cc Hatz Diesel Motorcycle

Go here for more information on the Sommer Hatz.


The Hatz 462cc 1B40 engine develops 11bhp.

Robin Enfield 412cc Diesel Motorcycle

Paul Holdsworth's ambition was to produce 200 of these machines a year but it is doubtful this target was ever met. However, about 100 bikes were produced and sold at the rather expensive price back then of £4500, the engine costing £1500 of that. Production started after the legendary diesel enthusiast Ernie Dorsett approached the company after first producing 5 G3 Diesel Matchless machines. Problems procuring the Matchless frames led all concerned to turn instead to the Royal Enfield. (Notice the error on the title photograph)Bikes began to roll off the production line in 1992.

The D R stands for Dorsett Robin

The Royal Enfield Taurus Greaves Diesel Motorcycle

Once available with either a 325cc or 436cc single cylinder 4 stoke Greaves engine these bikes are no longer in production according to the Official Royal Enfield website. Both versions of this bike have 12 volt electrics, 4 gears, 14.5 litre tanks and 18 to 1 compression ratios. This bike is no longer in production.


Probably the most massed produced Diesel Motorcycle to date.

Royal Enfield Lombardini Diesel Motorcycle

An older Royal Enfield with Lombardini engine.

Royal Enfield Lightning Diesel 435cc with Electric Start

I'm at something of a loss regarding this machine. If anyone has any hard facts please let me know. Perhaps its one of the last Diesel Variants before production stopped at Royal Enfield. The engine is a Lombardini.


The Lightning.

Sooraj 325cc Diesel Motorcyle


The Sooraj Automobiles of Saharanpur in Uttar Pradeshr, a company of India, offered this Motorcycle to the world in 1992 promising 86 km per Litre of Diesel. Using the trusty Royal Enfield frame it used a Lombardini engine. Details from Car and Bike Internation Magazine. Sadly the bike is no longer in production. Just been told the tank is from a bike called the Yezdi made by Ideal Jawa of India.

The D.E.R.A. Military Motorcycle

To those who take an interest in matters Military, it's common knowledge that NATO has embarked on a one fuel policy due to the fact it's cheaper and safer to have all their vehicles running on the same substance, ie: diesel. Obviously they had a slight problem when it came to motorcycles and both the British and United States Army's have embarked on various ventures to see how feesable it would be to convert existing bikes to diesel. The British converted a Royal Enfield engine to run on diesel and invited Fred Hayes of HDT over to try it out. Things went very well and R.M.C.S. landed the contract to design a completely new engine for the Marine Corps. After 2003 Petrol will no longer be allowed aboard U.S. warships and so the Corps needed to replace their existing bikes with something that used an alternative fuel.

This D.E.R.A. / R.M.C.S Bike (above) produced in1995 has an Enfield Bullet crankcase (beefed up) and a specially made top end which boasts 4 valves! It is of 547cc and produces between 16-18 BHP. Diesel injector is a modified unit from a car while the gearbox has but 4 gears. Apparently the engines flywheel is lighter than you'd normally expect to find on a diesel. The bike clocks 156 MPG @ 40MPH and 184 MPG @ 30MPH. The engine is mounted in a frame supplied by Eric Cheney. This bike easily pulls away from 250cc petrol bikes on cross country runs according to test riders.




SUPERCHARGER by Rynhart R&D - One that didn't make it into production.

The facts

Any owner of a Hatz powered diesel motorcycle would have been overjoyed at the prospect of being able to supercharge their machine. This looked very much as if it would be possible what with the progress made by Irelands Rynhart R&D in this field. An article detailing this companies development work up until 2002 is available from the Bullet-in magazine(see links page under literature), available on the internet (.pdf format).

Unfortunately things have taken a turn for the worse over the last year or so. Derek Rynhart told this site that he had been forced to call it a day and wind his company up due to the fact that his superchargers were too good. Combustion pressures of the Hatz 1B30 are 55bar but Rynharts supercharger put these up to 100bar which resulted in four broken crankshafts. The superchargers were O.K. on the bigger 1B40 engines but still there were problems. The engines fuel pumps could not generate enough pressure to get the diesel into the chambers.

It was with these problems in mind that Hatz told Rynhart they were not prepared to upgrade all of their engines to take account of the super chargers capabilities. Given that Rynhart managed to more than double the BHP of the 1B30, this is a shame for riders who ride 1B30 Hatz engined bikes. No doubt there are more details that may come out in time but those above give the main reasons why we will see no supercharged hatz motorcycles in the near future.


A Rynhart R&D Supercharger fitted to a Hatz 1B30 powered Royal Enfield.


This Hatz sure looks mean with that supercharger on.

Ashwins Taurus

This bike started out as a stock factory Taurus, but is now a very different animal. Barring the original Greaves power unit, almost everything else has
been customised to suit long range touring in India. Between the Diesel and my RE 500, I have coverd more than 80,000 kms on Indian roads and highways.
The diesel is obviously my mount of choice when riding solo on account of the economy it delivers, and the fact that unlike the petrol 500, it's
veritably water proof - a great virtue in the Indian monsoon.
Here's a quick list of the custom stuff on the bike.
1: Wide reach 'flat' handlebars ( a good 8 inches wider than stock). Helps handle the forward weight of the bike when fully loaded.
2: Long range fuel tank - holds 27 litres of diesel, side filler mouth with tank rack. Diesel quality in India is very inconsistent, so if one comes
across a good clean pump, one is wise to tank up. With 25 litres in the tank, I have a range of over 1500 kms :0)
3: Sprung saddle - not in pic, but usually goes on for 1000km plus rides.Neutralises a lot of engine vibration.
4: External oil tank - Holds 5 litres of 40 grade and has a tapped-pipe that feeds into the engine head. If oil level drops, just open the tap and top up :0)
5: Luggage roll bars. With over 20 kgs of stuff loaded, even a small drop can cause a big mess... hence the leg/luggage guards you see all over.
6: Saddle bags - not in picture.
7: Manual battery cutout. - Helps me control how much charge gets into the battery on a long day ride.
8: Auxiliary Riding lights - powered off a 9amp battery, 30 watts each, sourced off an old Bedford truck.
9: 18 tooth countershaft sprocket - adds 10kph to top cruising speed, HUGE virtue on this bike.

Royal Enfield 500cc Diesel Motorcycle.

Well, I just found that a company, Kristi, were given the job of turning an existing Royal Enfield diesel motorcycle into a mobile workshop and tool carrier to service all sorts of vehicles out in the wilds. It certainly looks different from the standard bike but I've no way on confirming that engine is 500cc.


A 500cc Diesel?

Royal Enfield Yanmar

This machine has at its heart a 750cc V twin Yanmar engine. This picture was taken at the Hamm 2004 Rally. The engine cover came off later but I only have that on video. I'll try and post when I can.

RE Yanmar 750. The 500 relates to what it was.

Royal Enfield 'Salad oil' Motorcycle

Built by the Altmann company this is a Royal Enfield Bullet complete with 406cc L100 'Yanmar' ( Kama KM186, Changfa) clone engine. I've put in in the Commercial section but you should be aware that the company is not producing them and so you cannot buy one as such. Although you may be able to buy the plans? You will have to enquire through their excellent website here.


Jan Vegter's Changfa Royal Enfield.

This machine started out it's life fitted with a Greaves engine but Jan tells me it was in poor condition and the 296cc Chanfa (6hp) was fitted instead. Apparently this bike dates from 1975 and was originally owned by MZ. Some frame alterations were made in this time before it belonged to the present owner. Jan can be contacted via the Brons Website. These guys supplied me with info regarding the very first diesel bike built in 1904 and seen elsewhere on this site.

A Diesel Royal Enfield with an MZ connection somewhere in its past.

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