The Enders 9061 petrol stove was produced in the 50’s and 60’s by the German company Enders. This company is still alive and selling outdoor products nowadays. It was in use in the West German army, the Bundeswehr. Other nations also used this petrol stove as part of the inventory of the German Leopard tanks. The stove is as German as it can be; Top notch quality, complicated design and lots of spare parts. The official name as stated on the type annotation plate inside the box is KOCHER, BENZIN, EINFLAMMIG. German language for Cooker, Benzine, Single flame. The NSN number was 7310-12-120-0877 and a very similar version of this stove, the Enders 9060D, was manufactured for the civilian market.
The stove is loved by many outdoor enthusiasts due to its good flame control and the ability to serve both small cups and big pans. The folding box design make it easy to carry and store. Although the weight is makes it quite heavy for your average backpack trip. Empty weight is 1,9 Kg and the weight of the stove + a full fuel tank is 2,2 Kg. People who like to bring no longer working stoves back to life (aka stove fettling) might have a hard time to do so with the Enders stoves. This article will give some guide to do this successfully.
Most of the no longer working Enders 9061 stoves have a pump that isn’t working anymore after 50 years. Rubbers and the leather pump cup are stiff and dried out. In in order to repair the pump we must first understand how these pumps are working.
First noticeable difference with the Coleman petrol stoves or Swedish kerosene stoves is that the pump (tube + plunger) can be removed from the tank. Both the Coleman and the Swedish stoves have a pump tube that is firmly soldered into the tank. Second noticeable difference is that the pump rod with the pump cup (plunger) can’t be removed from the pump tube. Or it can’t be removed easily. Only with some force they will separate. In most cases a flat rubber washer that keeps them together will break because it is brittle after all those years. If this happens you can replace this flat rubber washer with a O-ring (size 15 x 2 mm).
Plunger + leather pump cup
When the pump rod is removed from the pump tube you’ll notice a third difference. The leather pump cup has a different size. The diameter is 16 mm where the Swedish stoves uses 14 mm diameter for small stoves and 18 mm for large stoves. The US Army M1942 and M1950 stoves also use a 16 mm pump cup. Fourth difference is that the pump cup holder hat is permanently fixed to the leather pump cup itself. The pump cup leather is attached with a grommet to a backing plate into a permanent assembly that can not be separated. The original round spare part box that is clipped next to the fuel tank contained also a pre made assembly like this. Both Coleman and Swedish stoves use a pump cup leather assembly that can be separated into its individual parts so that in case of a failing pump leather you only have to install the leather itself instead of inserting a whole new pre made assembly. If you want to replace the 16 mm pump cup on your Enders stove you have 2 options apart from sourcing a pre made look a like assembly. One is to buy a 5 mm grommet set and use this to attach a thin backing plate permanently to the new pump cup leather with a 5 mm grommet. The other option is to buy a brass pump cup holder for small Swedish kerosene stoves. Usually you need to grind of a few millimetres of excess thread in order to ensure a loose fitting on the pump rod. This loose fitting is absolutely necessary for a correct working of the pump. The principal working of the pump is the same as in Swedish kerosene stoves; the pump cup holder with the leather pump cup is loosely attached to the pump rod. On the push stroke the pump cup holder is airtight closed while on the pull stroke the a little gap appears to avoid a vacuum. Only difference is that the Enders pump assembly uses a thin rubber washer to improve the seal of the pump cup against the pump rod on the push stroke. The Swedish stoves rely only on a metal to metal closing. The thin rubber washer can be replaced by a rubber O-ring (Size 4 x 2 mm) that fits loosely around the pump rod or a size 3 x 2 mm O-ring that sits more tightly on the pump rod.
Non Return Valve
The non return valve, the valve that allows air into the tank but not out, is also different. This valve can be found at the end of the pump tube. It is from the highest importance that this is not leaking fuel back into the pump. Since petrol is far more flammable then kerosene things can turn into a fireball quickly. Often the rubber that should ensure a complete closure is stiff or complete brittle. The fuel can then travel from the tank into the pump. Also the tank will loose pressure when the NRV is leaking. Resulting in a small flame when cooking. Therefore the rubber that is making a air and liquid tight seal should also be replaced. The Enders 9061 stoves were made with two different types of Non Return Valves. Before 1962 with a rubber pip just like in Swedish Kerosene stoves and after 1962 with a empty pip holder but with a rubber seating. The last system has a bigger contact surface and therefore a reduced risk of failure. It should be noticed that the rubber pip as used before 1962 is a little larger then in Swedish Kerosene stoves. The diameter is 5 mm where the Swedes uses 4 mm or 4,5 mm. Trying to use a pip that is to small will lead to problems as it won’t stay in place inside the pip holder.
Below are some pictures about changing a old stiffened seating for a new soft one.
Where to buy spare parts?
The two rubber rings are easily available in online spare parts shops. The small one on the pump is a 4 x 2 mm ring (4 mm internal diameter and a rubber diameter of 2 mm) The bigger ring for closing the pump tube is a 15 x 3 mm (15 mm internal diameter, rubber diameter of 3 mm). The pump cups are a bit more difficult. Fettlebox UK sells very smooth 16 mm leather cups for the M1942 stove and for the Tilley lamp. Since the Enders 9061 doesn’t have a pump cup holder of its own but one attached to each individual pump cup you have to organize something yourself. This can be done by attaching a thin metal or plastic washer with a 5 mm rivet to the leather pump cup. Another way is to install a Swedish small pump cup holder. These can be bought from UK based supplier www.tilleylampsandstoves.com. Complete sets of a 16 mm pump attached to a pump cup holder are also available on Ebay. Sellers gksk2146-3, Sefaudi, back*view and Chaowars Kocherteile Laden offer them as part of a larger Enders pump repair kit. Your best option for obtaining the 5 mm rubber pip (for stoves before 1961) and rubber NRV seating (for stoves made in 1962 and later) is German Ebay seller chaowars-kocherteile-laden He sells a variety of stove parts. Among them are many Enders stove specific rubber and metal parts. Please remember that in order to keep things safe it is from uttermost importance that you install a fresh fuel resistant rubber pip with the correct size (Ø 5,0 mm) or seating on your Enders stove.
Good to know
– The original wrench that sits in a clip inside the storage box is made of thin metal and can bend out of shape easily. Therefore it is better to use a regular size 14 wrench to open the fuel cap for refueling.
– The original user manual written in German language on the red type annotation plate inside the storage box suggest you to soak the fuel cap and pre heating cup under it with the petrol fuel from the fuel tank and to ignite this for pre-heating. Downside of this method is the strong formation of soot and big yellow flames. To avoid this it is better to use alcohol as a pre-heating liquid. A small bottle can easily be stored inside the box.
– The storage boxes of these stoves might be rusty or have the paint partly damaged. If you want to repaint the box in the original colour you should use RAL 6014 Gelboliv (RAL 6014 Yellow olive).