Hi guys, I know this isn't directly related to climbing, but I figure there are loads of climbers who use MSR stoves and that maybe one of you will be able to put me out of my misery by explaining how it works.

It seems like I just don't get enough fuel through to the burner and I've narrowed the problem down to the pump. Basically what happens is that only air comes though the fuel line and not enough fuel. I used my flat mate's stove's pump with my burner and then it works fine. I took the pump apart and inspected pretty much everything I can. All looks fine, the o-rings are in good condition and does not need to be replaced. I can't see any blockages and can blow though the fuel line fine (i.e. if I put my mouth over the filter and blow while the valve is closed it is sealed fine, but when I open the valve I can blow through it, which I think indicates that it seals fine and there are no blockages). Interestingly if I connect everything up and make ready to fire it up, it helps if I pick the whole thing up and shake it about a little. Fuel will then go through and I can light it up, but soon enough the fuel throughput will slow and eventually it will just die, unless I shake it up again. This is obviously nowhere near ideal to boil a pot of water, because you have to pick the whole thing up. Besides, it can't be safe shaking a hot burner around like that.

Some minor details: I accidentally broke the filter in half, but it didn't make any difference. I never thought about it before, mostly because it always just seemed to work, but how can you make sure you are able to use up all the gas? I mean, what if the fuel bottle is still half full, but the fuel line isn't submerged in the fuel, won't it just stop working. With my stupid brain I would have created a fuel entrance that is guaranteed to be at the bottom of the bottle (or rather side of the bottle that will lie on the ground).

I hope someone has some insights to share, I don't want to buy a new pump, those things are ridiculously expensive last time I checked.

You should contact Outward Ventures (021 671 4157). They are the distributors of MSR products, so they should be able to help you out. Afterall, the stoves have a lifetime guarantee.

Dude! just phone us O21 683 3638 (MSR agents)

I will look at that stove, free of charge I'll even replace that little filter for you.
Did you use your pump on your buddys stove the blockage might even be on the stove itself.
Perhaps the jet is blocked, which explains why it seems to work when you shake it) there is a tiny Pin in the jet that moves up and down and help clears any build up.

I look forward to your call, haven't had an MSR stove to fix in AAAAAGGGGGEEEESSS.
I'm getting rusty here.

Cathy

The no Crank has given is our Fax no.

oh good, my dragonfly also needs fixing (probably only a fuel line filter change). 5+ years and still going strong

Wow, that sounds good! Thanks Crank and Cathy. I kinda forgot about the life time guarantee. Cathy, I'll reply on your PM, but in the mean time I'll try it with my pump and my buddy's burner to make sure the problem is not with my burner. I doubt that's the problem thought. I have shaken the living daylights out of that shaker thing. I also pulled out the cable from the fuel line, and everything looks like it is in good working order. I even tried to start it up without the cable in the fuel line, but the same thing happens. Anyway, thanks for your offer to help, I'm impressed. One problem, I live behind the boerewors curtain, so I'll probably have to make use of our remarkable postal services.

The concept behind how these stoves work is actually very simple and only a handful of things can go wrong. From the sounds of it you are not able to maintain pressure through out the cooking process, this could be due to a leak (pressurise system and place in a tub of water to check for leaks).

The reason it will work when you shake it is that shaking temporarily increases pressure (try shaking a plastic container with petrol in it and you will find that it expands slightly)

Which MSR stove do you have and what fuel are you using?

_________________
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Thanks for the tip Nicolaas, I'll check for leaks when I get a chance. I don't think it is a pressure problem though, there is plenty air coming out of the jet. I mean before the burner is hot enough to convert the fuel to gas in any case. The one way valve at the bottom end of the pump was a little sticky, but it is better now and I'm sure it is not the problem. The pump itself does its job, building pressure. Not that I think it makes a difference, since they all work more or less the same, but I have a Whisper light stove and I always use benzine for fuel.

well well well, seems like I knew what the problem was from the beginning. From years of using and the way I pack my stove and pump into my pots, the bloody fuel line curved towards the air valve (i.e. away from the side the bottle lies on when you use it. This means.... wait for it .... no fuel! Like drinking milkshake with the straw outside the glass. I might be stupid, but I'm not pretty