How to clean a jetboil burner??

Try another can - more likely its the valve in the can not opening when screwed in.

Yep. Almost certainly the canister. My official jetboil struggles with some canisters. The gosystem ones seem to be the worst for it

As above, but try screwing the burner on tighter than you'd expect to have to, that can make the difference with certain brands.

It's not the can

I can get some gas through if I poke the hole from beneath them it clogs again

You probably need a gas jet pricker, super fine. I had a similar problem turned out it was dirt in the jet

There are normally some on eBay or random websites, keep one in the repair kit in case you get a blockage on a trip

I don't know about dismantling but Google is usually your friend. Alternatively I've found distributor' s to be very helpful. They may even send a pricker - I got a few o rings last time I asked

Alternatively you may be able to blast some compressed air back through the jet.

Hmmm I may be wrong!!

My leather lezyne track pump has the same thread and I can pump air through the burner 🤔 so tj et al may be correct BUT when I screw the canister on gas escapes 🤷 when I'm tightening it up then nothing comes out when fully screwed on and valve open 🤔

I have a tiny Chinese Ti stove. When I screw a canister on to that, and light the stove, gas comes storming out then fizzles out. Then I remember that I need to screw the canister on really tight to get the valve to open and stay open, then it's fine. Same canister totally fine with gentle tighten on my (not copy) Jetboil. So that's a +1 for "maybe you just need to get a bit more forceful when screwing it on, because the stove is a bit crap".

Weirdly the same canister but smaller worked fine before it ran out

manufacturing tolerances

Plus also a knock to the top of the canister can push the valve in slightly and thusly causing interference with certain stoves

I always check a new canister works before I go away. The one time I didn't, guess what happened 😒

The gosystem ones seem to be the worst for it

This has just prompted me to check the Go Systems ones I bought yesterday for my trip away. It definitely needs doing up tighter than the Primus ones and I’m convinced the flame isn’t quite as strong. I haven’t got time to switch for anything else now so hopefully they’ll be OK!

Kormoran - I also had that - and my spare can didn't work either.   No coffee in the morning.  I was not happy

Refund from Amazon incoming