Hello, I have a older whisperlite stove My pump broker a piece so i decided to purchase a new pump so i would not be left stuck in the backcountry with a stove that does not work. Well the new pump does not seem to be working. It is almost like it is too much pressure. It lights flames are huge, once heated up and primed, it goes out. I tried pumpin only 5, 10, 15, 20 to see if different pressure made a diff. same for all. using white gas
I completely disassembled, made sure jet was not plugged removed cable slide back and forth several times. It was running fine on old pump even though it had a crack in it
I am having a hard time following your description of what is happening. Could you provide a more detailed description of each step along the way (pre-priming prep, priming, lighting, running hot), what you did and what happens with the stove at each step? That will help decipher a possible cause. Also, is the bottle pressurizing when you pump it up? When you unscrew the pump does it release pressure?
Have a look at the pump and see which way the fuel pick up is. I wonder if its the oposite of your old pump and as a result its upside down which would put the fuel pickup in the vapour not fuel
I would check your fuel again. What you described sounds like the way alcohol would behave in this stove.
It is white fuel. I put my Ile pump in and it works fine. Put back new pump and I could get it going but it is like it is on high always regardless of how much I open valve
Can you try a friends pump & vice versa your new pump in their stove If its still not working contact MSR and tell the pump is fugausied and you want a replacement
I wonder if C/V is stuck and just needs to be poked. Like Swedish stoves when pip is stuck, until it breaks free and you hear the quoink of the NRV. Duane
Yes. That is a "feature" of the MSR pump. I can't speak to yellow pumps, but the new ones are tricky beasts to achieve anything other than full speed. But starting the stove, that shouldn't be an issue. I suspect your old pump is what you are used to, and the new pump is just a lot more efficient. The difference is making trouble. Use very little pressure to get your priming gas into the priming cup. Get this very little pressure by only 1/2 filling the fuel bottle and by then only doing a small number of pumps- try 2 and work up only if you have to. Turn the valve fully off. Prime very well until the flame is out, then open the valve 1/2 a turn to a turn while lighting at the burner. I'm very sorry if this is old news, but I don't know what you have been doing that works with the yellow pump. My grey or older grey/red pump instructions are a bit different. Now add just a little pressure, possibly just a few strokes. Do only enough to hold a flame. Your original VERY short fuel line will mean substantial pressure build up from heating the fuel bottle, so further pumping may not be required. If you do get the start working, check other threads for dropping below "rocket". To simmer you first need a stable, enthusiastic burn, so cross this bridge before trying to cut the flow back. Your other option is to explain to us, step-by-step, what you are doing- similar to what I have above. How full is the bottle? How many pumps before priming? How full is the cup? And so on. This will be got working. We promise. Or your money back (from MSR).
