Reviews > Cook and Food Storage Gear > Stoves > Primus AB ETA Multi Fuel Stove > Test Report by Jason Boyle

Primus EtaPower MF Stove

Test Series

Initial Report – December 11, 2008

Field Report - February 17, 2009

Long Term Report - May 23, 2009

Tester Information:
Name: Jason Boyle
Age: 31
Gender: Male
Height: 5' 6"/ 1.68 m
Weight: 180 lb/ 82 kg
Email address: c4jc "at" hotmail "dot" com
City, State, Country: Kodiak, Alaska, U. S.

Backpacking Background:
I have been camping and backpacking for about 20 years. My introduction to the outdoors started with the Boy Scouts of America and has continued as an adult. I have hiked all over the Southeastern, Northeastern, and Northwestern United States. I am generally a lightweight hiker, but will carry extras to keep me comfortable. I currently reside on Kodiak Island in Alaska home of some of the worst weather and most beautiful scenery around. I look forward to putting gear through the paces here on the Emerald Isle.

Product Description:

The Primus EtaPower MF is the multi-fuel version of the EtaPower EF, an LP gas stove that debuted in 2007. The updated version has been designed to burn multiple fuels – LP gas, white gas, gasoline/petrol, and kerosene. It includes a stove burner, aluminum wind screen, pot with heat exchanger, lid/frying pan, pot gripper, insulated carrying case, instruction manual, multitool, 3 different jet sizes for the burner, 350 ml/10.6 oz fuel bottle, ErgoPump, and a small tube of silicon lubricant for the pump. The pot, windscreen, burner base, and lid appear to be made of aluminum, have a silvery brushed matte finish on the outside. The pot and frying pan/lid have a titanium non stick coating that is dark in color. All of the items listed in the description fit snugly inside of the EtaPower pot. The stove burner consists of two parts; the burner and a pot support ring. The burner slips into the middle of the pot support ring via folded metal tabs that hold the burner in place. The pot support ring has folding pot supports with serrated edges. The fuel delivery tube runs around the edge of the burner head, then over a small cup that has a fabric wick before entering the burner. Fuel drips into the small cup and soaks into the wick. The stove is initially lit at this point, which allows the liquid fuel to be preheated and eventually atomized into a gas when it flows into the burner. There is a small knurled nut that connects the fuel delivery tube to the burner head that can be unscrewed by hand to change the jet to match the various fuels that can be used with the stove. The multi tool has a wrench and a box end which must be used to unscrew the jet. The three included jets have a small opening that allows the fuel to be properly atomized in the stove burner. The LP gas jet came installed in the stove.

The ErgoPump is a very interesting pump. It has angled threads so that the pickup tube goes into the fuel bottle at an angle, instead of in a straight line with the opening. There is text on the outside of the pump that says “On” and “Off”. When the word “On” is displayed the pickup tube is in the fuel, when the word “Off” is displayed the fuel pickup tube is either not in the fuel anymore or there is some sort of check valve that keeps the tube from picking up fuel. The side of the pump has a threaded connection to connect the metal fuel line from the stove to the pump.

The windscreen looks like a tall walled bowl that has a large hole cut in the middle. The center hole is designed to fit over the stove burner with the pot supports folded in then to be turned just slightly clockwise. There are three small tabs to that hold the windscreen in place and on one of the tabs there is a small nipple that helps to hold the wind screen securely in place. After the windscreen is in place over the stove burner the pot supports can be folded out. The windscreen is about 8” (20 cm) in diameter at the opening and the pot is about 6 ¼” (16 cm) in diameter at the bottom so there is a small gap between the windscreen and the pot. The windscreen is tall enough that it covers the heat exchanger on the bottom of the pot but not much more.

The pot is similar to any other pot except for the integrated heat exchanger on the bottom of the pot. I cannot tell exactly how the heat exchanger is attached to the pot. There are no apparent welds that I can see, or they are really cleaned up very well. I know from experience that thin aluminum is very hard to weld cleanly. The pot is completely smooth except for a rolled lip. There is a Primus graphic on the side wall of the pot and on the opposite side of the graphic there are stamped measurement lines in 0.4 l (0.4 qt) increments starting with 0.2 l (0.2 qt) and ending at 1.8 l (1.8 qt) just below the lip of the pot. The frying pan/lid has been updated from the original EtaPower release and now has a small indention in the bottom of the lid so that it fits nicely into the top of the pot. The pot grippers are similar to other lightweight pot grippers except that they have two small rubber disks on the side that touches the inner pot so the gripper doesn’t scratch the non stick surface. Nice attention to detail! The insulated carrying case appears to be made of non-coated ripstop nylon inside and out. There is a YKK zipper that runs the circumference of the top of the case and a smaller zipper inside of top of the case that opens into a small top pocket. Both zippers have a small piece of bungee attached to a rubber pull tab. I am not sure what is between the inner and outer pieces of nylon but it feels like there is another material that may help with the insulating properties of the case. There is a large Primus EtaPower graphic on the very top of the case and a webbing carrying strap on the side. The included instructions have the usual warnings that come with a stove – use in a well ventilated space, don’t use in a tent so forth. It also included instructions for use with each type of fuel and how to change the jet to burn each type of fuel. There are multiple graphics with numbers on the front of the instructions, and the text instructions inside the booklet refer to numbers which I assume are supposed to refer to the front graphics; however the text numbers and the graphic numbers do not correspond. That being said I was able to look at the graphics and figure out how to change the jet with no problem.

Initial Impressions:

As an owner of the Primus EtaPower EF, I had a good idea of what to expect. I am impressed with some of the upgrades that Primus has made to the new EtaPower MF. The new lid/frying pan with the indention made to sit snugly on the top of the pot is great. I also like the addition of a locking tab to hold the windscreen in place. The stove arrived with all the pieces stored inside of the pot and carrying case like a big jigsaw puzzle. However, I don’t think I am going to try and store the liquid fuel bottle and ErgoPump inside of the stove kit. I like to keep my white gas stored somewhere on the outside of my pack. I took the stove out to the shop to give a test run. The first thing I did was change the factory installed jet so that I could use the stove with white gas. I unscrewed the knurled nut, and then used the multi tool to unscrew the factory installed LP gas jet. The jet was in there very tight and it took me several tries to get the jet loose. I was afraid to put very much strain on the fuel line since it is a standard brass line. I managed to get it loose without breaking anything which was good. I installed the white gas jet to a hand tight level and reassembled the stove. Like most white gas stoves, the user pressurizes the fuel bottle using the included pump and then opens the fuel valve to let a little bit of the gas onto the wick. The user then lights the wick which preheats the fuel delivery line so that the fuel will be atomized going into the stove burner. Once the fuel line is preheated the fuel valve can be opened again and the stove is ready to be used.

I followed the directions that I listed above, but I had the windscreen installed over the burner and realized there was an issue. With the windscreen installed I could not get a lighter to the wick in a safe manner, if I had a match though I could light it from underneath or by sticking the match down to the wick. Like other white gas stoves, once I lit the wick there was a large orange flame that burned for a minute or so, as this flame died down and there was a hiss and a blue flame coming out of the burner. At this time I opened up the fuel valve to fully operate the stove. A nice blue flame arose from the burner but after just a few seconds fuel and a flame shot out of the knurled nut where I had installed the jet. This was quite scary. I immediately shut off the fuel and let the stove cool down. Once cool, I disassembled the stove and tightened the jet with the multi tool. I reassembled the stove and went through the lighting sequence again. Tightening the jet did the trick, I was able to get a nice blue flame from the stove, and no flames shooting from places they were not supposed to. I did a quick test of boiling time with the stove. It wasn’t laboratory conditions, but I like to include this type of information. Air temperature was around 37 F (3 C), and there was no wind in my garage. Approximately 1L/1 qt of water taken from the outside facet was put into the pot and I put it on the stove after I had already preheated the stove and had a steady blue flame. At the stated 2.5 min boil time there were large bubbles in the bottom of the pot, at 4.5 minutes there was a roiling boil. I am not overly concerned with this time, and I don’t backpack in laboratory conditions, so I don’t get too wrapped around the boiling time. I can usually find various camp chores to do while my water is heating up. The size and weight of the system make it a good choice for a group, but might be a little overkill for my solo trips. Primus doesn’t specify what components of the system they use for their weights, but based on the measurements that I took everything is quite a bit heavier. I look forward to playing with this stove this winter here on the island and see how well it performs in the rain, snow and ice of Kodiak.

Summary:
So far my results have not been good. On both of my trips, the stove didn’t want to preheat using white gas and as a result the expected blue flame rarely appeared. I was able to get my water hot enough to cook my meals, but it was quite a challenge. I have contacted customer service and done some trouble shooting. The white gas jet was gunked up and that may have been the culprit. Hopefully, the next couple of months will result in better results.

Field Conditions:
I have used the stove on two overnight backpacking trips. The first trip was to Termination Point and the temperatures were between 20 F and 32 F (-7 C to 0 C) with winds between 10 to 15 mph (16 to 24 kmph) and a light dusting of snow overnight. The second trip was to a point over looking Pillar Beach that doesn’t have a name. Temperatures were between 10 F and 14 F (-12 C to -10 C) with winds up to 20 mph (32 kmph) with intermittent snow showers.

Report:
Normally, I would evaluate stoves on two main characteristics – durability and usefulness. However; I have had some serious issues while using the stove with the white gas configuration that I will detail below.

My first trip was to a fairly open camping spot called Termination Point. Stove set up was fairly easy and as I mentioned in my Field Conditions, there was a steady light wind. I followed the directions, pumped the stove about 20 times, allowed a bit of fuel to drip into the primer cup, then lit the fuel in the primer cup. The stove preheated like it did in my garage, but it never seemed to warm up the fuel delivery tube enough to generate a steady blue flame. I futzed with it for about 45 minutes relighting the primer multiple times and finally got a mostly steady flame. The stove worked enough that I was able to heat up water for tea, and to cook a basic Lipton rice meal. If I had not been testing the stove, I would have given up after about 15 minutes or so and just had a cold meal that night. The next morning, I chose to forgo a hot meal for breakfast and just ate some snacks that I had brought along before my hike out.

Once I returned home, I tried to figure out what might have caused the stove not to work properly and the first thing I thought of was the fuel. I was using some white gas that I have had for a couple years. So I emptied the fuel from the fuel bottle and bought some fresh Coleman White Gas. Armed with fresh fuel, I took the stove on my second trip. However, the stove performance was even worse this time. Again I followed all the directions to the tee, but the stove would not preheat. All I was able to coax out of the burner was a yellow sooty flame. For whatever reason the stove never warmed up enough to produce a blue flame. I was able to boil water on the stove with yellow flames flowing up the sides of the pot, but this was less than optimal and very frustrating! Once again, I had a cold breakfast the next morning because I didn’t want to fool with the stove again.

After my second trip, I tossed the stove in the gear closet in frustration and left it there for a couple of weeks as I pondered what to do next with it. I also contacted Primus to see if anyone else had reported any issues with the stove and I am awaiting a response from them. In the mean time, I tore the stove apart to see if I could identify a problem and I may have found the culprit. The entire jet face was black from soot, so I cleaned off the soot on the face of the jet and used the included stove tool to clean out the jet itself. I then set the white gas jet aside and reinstalled the LP gas jet to see how the stove performed in this configuration. Using a partially full gas canister I had laying around, the stove lit up immediately with a nice blue flame. Since the stove seemed to be working properly, I did a test run where I boiled a liter of water. The canister was partially empty four season fuel mix, and the outside temperature was 30 F (-1 C) with no wind inside my garage. It took about 9 minutes to boil a liter of water taken from my outside tap. Not too bad, but much longer than what Primus advertises.

After the stove had cooled from my canister trial run, I reinstalled the white gas jet. I followed the directions and lit the primer cup. I let it preheat until the flame was almost out and then opened up the fuel from the bottle and a nice blue flame appeared in the burner. After letting it run like this for a few minutes, I let the stove cool down and disassembled the stove again to see if there was any soot buildup on the jet. There was none. I am encouraged by this result and hopeful that the stove will operate properly in the future and that the issue was just caused by the old gas I had originally used.

Since I spent so much time troubleshooting the stove, I cannot comment at this time on the fuel efficiency of the stove. However, I hope to be able to analyze this more as the test goes on. As expected the pots and all other components seem to be well made. Clean up is very easy, I was able clean the pots using some warm water and my fingers or plastic spoon. The included case is great for keeping water hot or helping to cook food that requires simmering. I think this whole system is a great idea and as an owner of the Easy Fuel Eta Power system, I have a good feel for what the system is capable of doing, but haven’t been able to get it to perform yet in the field.

Summary:
As I mentioned previously, I contacted Primus Customer Service and it turns out there was an issue with the fuel delivery tube on the previous stove. They replaced my stove and the new stove worked better, but not great. The system is great for cooking for a group and the multiple fuels makes the stove useful in a multitude of conditions. However, I still have a few durability concerns with this particular stove.

Field Conditions:
I used the stove on a 6 day trip to Uganik Lake, on a remote part of Kodiak Island that is accessible only by floatplane. Temperatures on this trip ranged from 20 F to 65 F (-7 C to 18 C). Elevation was 75 feet (23 m) above sea level and for a majority of the trip the wind was a constant 10 to 20 mph (16 to 32 kmph) with no precipitation experienced. The stove was used outside on the deck of a cabin, in the field, and on a counter inside the cabin.

Report:
I had a rough time with the stove as I outlined in my Field Report so I contacted Primus Customer Service via email. It took them a while to get back to me but they did and confirmed that there was an issue with the stove. Apparently the fuel delivery tube needed to be bent to go over the edge of the burner instead of around the outside of the burner. Primus sent me instructions on how to bend the tube into the correct place, with the assurance that if I broke something they would replace the stove. Apparently they know me well, because in the process of trying to bend the fuel delivery tube, I broke off the priming cup. I contacted Primus customer service again and they shipped me a new stove. This one had the fuel delivery tube routed over the corner of the fuel burner instead of around the burner as with my previous stove.

Once the new stove arrived, I set it up and did several test runs with it and it performed well each time, so I felt comfortable enough to take it on my trip to Uganik Lake where I would be cooking for me and my two trip partners. We did bring a back up stove just in case the Eta Power MF had issues, but I had much better results on this trip than on my previous trips. The stove worked as advertised. I was able to use it to make multiple meals for the group including quesadillas. I was also impressed with how many times I was able to use the stove on the small fuel bottle that was included with the stove. I was able to cook 16 quesadillas, and heat 4 full pots of water for oatmeal and coffee before needing to refill the bottle. This may not seem like much but quesadillas take forever, I think it took 45 minutes to an hour to make the quesadillas for the group with the stove running constantly the entire time. Once I refilled the bottle I didn’t need to refill it the rest of the trip, and I was using it to heat water at least twice a day.

Part of my trip included using an inflatable boat with motor to explore the lake. This was a particularly long day and I took the stove with us. After a sunny, but chilly day of exploring I decided I wanted some coffee before heading back to our cabin. I set up the stove on the lee side of the beach which was fairly protected but there was still probably 10 mph (16 kmph) of steady wind. Surprisingly, the wind had a serious effect on the stove’s performance even with the “windscreen” installed. My observation was that the wind was blowing from underneath the stove and causing the burner to flicker. The flame was blue and strong but it took a good 10 minutes to heat two liters (quarts) of water to a boil for coffee. I am quite surprised by the impact the wind had on the stove’s performance, I didn’t expect that.

There are a couple of areas though that I am not as excited about with the stove. One is the burner attachment. The burner snaps into pot support ring. However the connection is very flimsy and the burner would come unsnapped very easily if I adjusted the stove or the fuel bottle. I found this to be very unnerving especially when it happened while the stove was lit. I have tried to adjust the tabs on the pot support ring to hold the burner more tightly, but to no avail. It isn’t necessary to remove the burner from the pot support ring to pack the stove away, so I am unsure why Primus has decided to make them two separate pieces. I would really like to see these two pieces become one single piece. I think it would make the system a bit safer and sturdier. There were several times where I would light the primer cup and then the burner would become unattached from the pot support ring and fall down causing the forest detritus under the primer cup to catch on fire. This was unnerving especially with the wind at Uganik Lake. The burner set up works fine with LP Gas which doesn’t need to be preheated in the primer cup, but doesn’t have the same performance as white gas in cold weather.

As I mentioned previously the pots were super easy to clean and the non stick coating worked well, even with burnt cheese from the quesadillas. The carrying case also worked well as an insulator. I would routinely cook a meal about three quarters of the time required and put it in the insulator to finish cooking. I could also boil water for hot drinks and by storing the pot in the insulator I was able to drink my first cup of tea and still have hot water for a second cup. This is a great feature and I am surprised that more pot manufacturers haven’t designed custom insulators for their pots. The pot size is a perfect fit for groups. I was able to cook meals for three in the pot with no problem.

In conclusion, the Primus Eta Power MF, is a good concept and performs well. The pots and insulated carrying case are great features and the pot is big enough to cook meals for three people easily. However, I feel the burner assembly needs to be improved for me to continue to use this product with white gas. This concludes my Long Term Report. Thanks to Backpackgeartest.org and Primus for allowing me to participate in this test.

Reviews > Cook and Food Storage Gear > Stoves > Primus AB ETA Multi Fuel Stove > Test Report by Jason Boyle