ECHO backpack blower carb replacement
 

Once again, I am on the receiving end of a FREE piece of equipment that has sat for many years. This time it's an ECHO PB-403T backpack blower from 2005.

I replaced the spark plug (due to no spark) and primer bulb (since it fell apart), and managed to get it to run. But the next day it won't fire up. I replaced the air and fuel filters, but still getting no fuel into the cylinder. So I guess some sediments or something got sucked from the tank and gummed up the carb.

I ordered a new OEM carb and gaskets, is there anything special I need to do as far as high/low adjustments? Or do these OEM carbs come ready to go from the factory?

If it’s adjustable at there’s special tools. The screws have odd ball heads on them.

I would check the service book, often 2 cycle stuff now comes somewhat adjusted and "capped". You can remove those caps and use the aforementioned screwdrivers to dial it in.

https://www.farmandfleet.com/product...waAlWxEALw_wcB

Be sure you have the correct mix, spark plug and such.

https://www.echo-usa.com/getattachme...1c2873/filev1_

I used an official echo tune up kit with the air filter, spark plug, and fuel filter. Spark plug gap is .65 as the manual states. Fuel is 50:1 mix as manual states.

Even with the brand new carb it runs rough, won't idle half the time, or hesitates a lot. The new one came with limiter caps in the box but not installed, so I assume it needs adjustments and put those one once it's set? But I have idea where to start with the adjustments...

I'm not familiar with Echo's but other brands have problems with the exhaust clogging up.
Remove the muffler and you may find a fine mesh screen, inside the muffler or on the input. That screen can clog or there may be excessive carbon inside the muffler.
Worth a looksee.

I will try and clean the spark arrestor screen this weekend. If still not running right, I found a local shop that said they will only charge $25 to tune the carb. They said they can do it while I wait, not even 15 mins provided nothing else is wrong. I don't foresee anything else being wrong, as I've literally done all user serviceable parts at that point!

Well I couldn't get the muffler off to clean the spark arrestor (too rusty). But I found the problem. When I initially installed the carb I had to reuse one of the old gaskets due to the one it came with being damaged. I replaced it just now with a new one and it fired right up no issues! No hesitation or anything it just runs and blows fine