Carburettor Oddity

I was hoping someone might shed some light on an odd phenomena I've been experiencing.

Occasionally my 1500 loses power and I assumed it was fuel lock due to hot temperatures but it has also happened now on a cold engine. When it occurs the engine won't run nor pull at low and medium revs, it just dies and will only run at very high revs. If I pull over and remove both emulsion tubes and both idle jets then replace them again it cures the problem and the car continues running perfectly normally. I inspect the tubes and jets each time I remove them and they appear clean and unblocked.

Seems strange to me but there must be an underlying issue/cause? Any help would be greatly appreciated. One emulsion tube has 107 inscribed, the other 130. Thanks.

Mike, my first thought would be fuel filter or maybe a blockage at the tank. As you suck the offending body into the route of the fuel it blocks and restricts supply. After you stop it would naturally drop away within the time it takes you to do your emulsion tube remedy. Have you checked wether you have fuel showing in the filter when the fault occurs? Of course the same goes for air restriction, check just to make sure something is not flapping over the air intake.

Hi Andy and many thanks for taking the time.

That sounds like a promising lead. I haven't checked the filter when it happens but I will do next time; I will also just leave everything alone and try restating after a few minutes - approx the amount of time I would have spent fiddling with the carb on previous occasions. I'll check the air intake also but I'm pretty sure it's unrestricted. I'll let you know how I get on.
Thanks again
Mike