Bushwalk Australia

Just back from an Easter weekend in the Snowies and I encountered a frustrating problem with my Jetboil Flash.
The gas flow was fine with the first (almost empty) MSR isopro cylinder but when I screwed it onto another full MSR cylinder I couldn't get any gas flow at all when I tried to turn it on.
Luckily I had an old Pocket Rocket with me and that worked just fine with cylinder #2. But it could have been a very ugly weekend without the Pocket Rocket backup and no way to boil water.
I should probably get a third cylinder and see if the Jetboil has the same problem but I was wondering if anyone else has heard of any similar problems?
Kym

I've had some issues with canister gas flow in stoves. It's likely that the problems weren't all due to the same cause. The most recent instance I discovered with some surprise that I needed to twist the canister on just a little bit further, like an extra 1/4 turn beyond where it felt as tight as was normally required to make a connection. I don't know why this was necessary, whether it was due to some oddity in the canister or my stove. Twice previously I've had stoves that I think developed some sort of clog in the gas path, threatening trips with poor or no flow. Those two stoves were retired, although the second of them I now use at home to make coffee and it's working just fine. Maybe I wasn't screwing the canister on enough for that one either? Perhaps I should spend more time in the gym.

There was a thread about this problem either here or at BPL where it was pointed out that some cartriges needed a slightly longer pin to be activated (well, something like that anyway)
The other problem of stove getting clogged up was dealt by Roger Caffin at some point also at BPL (maybe here too ?) so maybe he will pop in with some comments on this.

If one canister works and another doesn't then the problem is due to the distance between the top rim of the canister and the point where the valve is sufficiently depressed to release gas. It is not a stove problem other than the length of the pin which depresses the valve when the stove is screwed onto the canister is a little short, but the real culprit is the manufacturing tolerances of the canister. Usually tightening the stove harder onto the canister removes the problem but too much tightening starts to damage the internal thread on the stove as the metal in the stove is softer than the steel canister.

I've given up on relying on my BRS-3000T stove as it has had more than its fair share of problems. But it's is so light and tiny it is the perfect backup stove. It's quite a desperate feeling when your stove is malfunctioning and all you have to eat is spaghetti.

Try a different brand of gas canisters. I use mainly Elemental canisters and have had no problems using on a light stove that some others have had the same difficulties as you.

When there's a $ involved, consider conspiracy first?

I'd suspect the pin length (as said), may have just screwed on to the first can down further or yes, dodgy tolerances.
Seen this mentioned with coleman and msr.
Here's a discussion, and interesting fix.. https://classiccampstoves.com/threads/c ... ail.35129/
A wee pebble for the desperate

In the two cases I mentioned I was using the same brand of canisters without any problem prior to encountering a problem.

I was using Elemental canisters without problems with the stove I assumed got clogged. We tried both canisters, it didn't matter. That stove seems to work now so maybe it unclogged? Who knows. It seems unlikely that both of those Elemental canisters were bad.

The more recent time, when screwing it down tighter fixed the issue, I had a brand new stove and two Jetboil canisters. But I had been using Jetboil canisters without problems. So I don't understand that case either. Why would the canister I'd been using suddenly change? The other one was the same. Maybe my arm felt weak for some reason, I don't know. It's just weird.

Thanks all for the feedback. To the naked eye there is a difference in pin length between the Jetboil (shorter) and the Pocket Rocket (the opposite of shorter). There's no blockage because the JB works with cylinder #1 but not with cylinder #2.
I'm thinking that there must be some manufacturing/quality control hiccup with cylinder 2 where the valve is marginally lower than the other one.
Or it's just gas cylinder voodoo.

some manufacturing/quality control hiccup with cylinder 2 where the valve is marginally lower than the other one.

Yup.
If the Lindal valve crimping machine is not adjusted properly, the top of the gas nipple can be lower than it should be. Known problem, but it makes life difficult.

Cheers
Roger