I have a Echo PB 2601 made a loud bang then stoped working.

50:1

Not sure what carb you have..You should be able to see a spring loaded air/gas adjustment screw on the carb..once running turn clockwise until motor starts bogging down then the other way until it does the same..keep adjusting back and forth unti it runs smooth..
you may have another on the bottom of the carb bowel..do the same with it...if this doesn't work needs a rebuild kit..good luck..

most new machines are 50:1

Issues like this could well be a ignition unit breaking down when it gets hot.

if it has spark and doesn't fire on starting fluid try taking off the muffler and run it if ok open the muffler and clean the screen off

i have aecho pb 260l backpack style leaf blower and it will not start. it turns over well and has spark and reasonably new fuel. any thoughts

My echo uses 50-1 ration. Home Depot sells the small containers for Echo Leaf Blowers that you mix with one gallon of gas.

I just fixed my Echo PB 2100 with the same issue. It would start, run, all throttle openings OK but would not rev-up. It was a dirty/clogged screen on the muffler. Scraped the thick tar off then used Lacquer Thinner to soak it clean. Blower works better than ever now....

Had the similar problem- start with removing the exhaust intake plate 1st--- clogs with super fine dust initially then larger particles... Mine was completely clogged- cleaned er' out now she blows like the wind!

these do this all the time just let it sit for 10 minutes and it should fire back up.