echo PB500h backpack blower no power

[ACF]

have a echo pb500h backpack blower it will start but not increase speed in order to increase wind speed could it be the carburetor any suggestions would be great
thank you in advance

 

[ILENGINE]

Check the spark arrester screen in the muffler. If clogged with carbon will cause a no accelleration

 

[ACF]

Check the spark arrester screen in the muffler. If clogged with carbon will cause a no accelleration

finally got the guard off for spark arrester and it was clogged
thanks