Recently the Primus Gravity MF (multi-fuel) stove became available on several websites at great discount. This was of interest to me as I noticed that the stove package includes a Ergo pump. The sale price for stove and pump was less than the pump by itself, so I thought I'd give one a go. Note that the box mentions an "Instructional DVD" included. True. But not for this stove. Rather the DVD covers other stoves and gear in Primus' line-up. The box contains the DVD, a bag for the stove, a sweet Ergo pump, the stove, a windshield, a multi-lingual instruction sheet and a small bag of items rubberbanded to the pump (one of which has fallen out of the bag in this photo). The small bag contains a tube of silicone lubricant, two jets (for kero and for white gas), and a stove tool which includes the pricker. Top and bottom of stove. If these components look to be made of flimsy and easily bent metal to you then your powers of observation are very accurate. The stove came with the LP gas jet installed, so I fired it up with that in place first. Sadly, a whole area of holes in the burner do not seem to receive any gas! There are similar areas of no-gas near the back of the stove. And, this is the only simmer I could get out of it. Well, me thinks, maybe it'll work better on white gas. I'll just change that jet..... huh? Wow! Looks like I have to take the whole stove apart to do that! Although the stove is held together with only one screw, in order to reach the jet for replacement, a complete disassembly is required. This is difficult to do without bending the parts of the stove or the generator coil. The clever among you have probably realized that the same problem exists if you want to clean the jet with the supplied pricker. Yep, disassemble the whole stove in order to get at the jet to clean it with the pricker. The included paper manual does not discuss how to change jets. At all. Not a word. Here I've unscrewed the LP gas jet. And, here is the white gas jet in place with the LP jet on the side. It took me two tries to get the parts all back together correctly. They all need to lock together just-so before the screw can be rotated home. There does not seem to be a preheat pad anywhere that I could find on this stove. Hmmmm, how to preheat it? I chose to have a big bucket handy in case I had problems. Releasing a small amount of fuel into the stove I lit it. Preheating. The problem being that fuel in the generator expands and squirts into the stove. And, then it finds it's way to the vents in the bottom of the stove pan and drips out the bottom of the stove. Burning fuel, mind you. Under the stove. That happened right after I took this shot and right before I grabbed the bucket and inverted it over the stove to extinguish the developing fireball. A fireball can do a pretty good job of preheating, so removing the bucket and carefully cracking the valve open....... I was able to get the stove lit and running with white gas. It still simmered badly. And, it still had a large bank of holes that exhibited no flame. You can see from above that a good portion of the stove does not seem to have flamelets at all. Now, if you're wondering how it performs on kerosene, I'd have to say that I have no idea. Personally, at this point I've had enough and I don't plan on researching this anytime soon. Suffice it to say that there are a number of issues with this stove. 1. Flimsy, easily bent or damaged components 2. a badly designed or defective burner that has banks of holes that do not receive fuel/air mix. 3. No clear way to preheat the stove without starting a forest fire. 4. a design that necessitates disassembling the stove to change jets or even to clean the jet with the pricker. The only good part? A really sweet Ergo pump. And, by the way, the fitting at the end of the fuel hose that attaches to the Gravity stove is a completely different size and thread from the connection that is used on a Primus Omnifuel. So the hose from the Gravity may not be used with an Omnifuel without physical modification of significance. There you have it. I tried it and now you don't have to. Final opinion? *ahem* It's a bonafide 100% loser of a stove - worst I've ever lit. Usual disclaimers apply. Cheers, Gary
I guess they really don't make them like they used to :frown: About the pre-heat thing, on Youtube I've seen them pour meths on the side ring of the burner and light that. Dunno if that will help to pre-heat?
I reckon any stove that you have to strip , in order to clean the nipple is a NO GO . Cynical proffering from a company who had a reputation for making quality, user friendly ,products. Nick
Perhaps there is too much of a rush to blame arsonists for forest fires? Maybe they are caused by innocent Primus MF users too embarrassed to come forward and admit they bought and used one? Cheers, Graham.
thanks for the writeup - quite disappointing that the Primus (and Optimus) brand names are being diluted by poorly engineered and constructed products - simply amazing that this stove made it to manufacturing? (not a first from any manufacturer, as i've learned from the expert historian stovies here)
