Echo pb-260l won't rev up under load. like it is missing. changed plug, fuel filter, fuel line, carb. change fuel to meet precise specs. Ideas?

Wow! with all you have done it should run. Be sure the switch is on but if you are getting spark, it should be on. I would take it to the echo place for service.

I'm 99.9% sure it's the fuel line. The ethnoll in gas really shrinks the oem fuel lines

I have installed new carb kit, fuel lines, plug, and air filter. Blower continues to bogg down when opening up throttle. echo 770 blower any ideas?

Hi dbooth
Make sure your fuel lines are connected correctly.
Check the drawing below
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Bud

on a 2 cycle engine change the spark plug and air filter fresh fuel

Check the exhaust port upstream from the muffler and make sure it is not restricted with carbon. Mine was less than half way covered over with carbon. Scraped out carbon, checked muffler and screen(ok), back-blow the fuel line harness including the fuel filter and fuel tank vent and took carb apart and blew out all passages, not replacing anything and now runs fine. Would not rev past high idle before. Be sure gas is FRESH and mixed at 40-50 to 1. Hope this helps.

check carb and clean jets

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

guarantee exhaust is clogged maybe not muffler but exhaust port pull muffler off check screen and muffler then look into exhaust port usually rectangular port is closed down with carbon pull starter slowly to lower piston then scrape out carbon with screwdriver clean as good as possible then blow cylinder out make sure to get all pieces of carbon out reassemble should run fine

Too much oil in gas.