I thought I made a cat can stove but i some how managed to make it not work. I used a 3oz tin. Punched holes in the side just under the lip and also another row, offset to the top row.
Maybe my fuel is no good? I'm just using methylated spirits from a petrol station. It says 95% ethanol minimum. on the front.
It lights but the flame just burns very poorly when a pot is on top. I can see a slight blue flame but it does not come out of the side jets.

Did you prime the stove before putting the pot on? You have to let it burn for 20-30 seconds so that the fuel gets so hot that it's boiling. After it reaches this state, you can put a pot on it. If you put the pot on before priming is complete you get results like you described: weak flame, not shooting out of the holes, etc.

Good luck.

Once the alcohol in it "boils", then put the pot on. Takes longer when colder or just a few seconds at 70 F.

This site has thorough instructions.

If you punch the holes a little lower, they will allow the flames to keep the stove hotter and have a better boil time, and quicker start up. Just make sure they are high enough to hold enough fuel in the stove.