Why wont my brand new Ryobi 04820 42cc blower start?

SOURCE: FL 1500 blower won't start

I have the same problem with mine . The FL 1500 model is a older model and the lines that run from the tank to the carb could be brittle and cracked like mine . The only way mine will fire is to spray starting fluid in the carb . It will run for a short time and die like its not getting fuel and everything else checks out ok and im trying to find a new tank and lines for mine at this very moment . The lines had cracks in them everywhere and i believe you have to buy the lines and tank as a unit so if i can find one and get it working ill let you know .

SOURCE: Ryobi RBL30MVA petrol blower problem

if this is a brand new I would ask is the gas oil mixture fresh and of the proper ratio. most use 40-1
if this is not brand new look and see if the muffler could be clogged up. a common problem is the spark arrestor screen gets clogged up with carbon deposits.

SOURCE: someone ran gas instead of 2-cycle in leaf-blower; now locked up

It's probably dead. If the rope won't pull buy another and keep it for parts, the repair bill will be more than it costs. Spray some wd- 40 in the spark plug hole and let it sit for a couple days, IF it frees up you got lucky but don't expect it.

SOURCE: Ryobi 720r weedeater. Starts, stalls, won't start.

When you rebuilt the carb did you remove and replace the welch plugs. If you did not, then that is probably where your problem is. Debris, varnish and corrosion can build up under the welch plugs and the unit will not pass fuel.

SOURCE: Low RPM's Ryobi 25.4 cc backpack blower

you need to adjust the carbarator