Stihl BR 320 Backpack Blower

[fredeerick]

Little used older machine but recently it's having what seems a fuel draw(?) issue.
It will run acceptably with the choke on about 1/3rd closed.. but nowhere else. Prior to the carb clean it would seemingly fuel starve after 15 mins running . Revs would drop and if left to idele for a min would rev up nicely again for a couple of mins.
And NO it wasn't seizing as far as i can tell. :-)
Cleaned the carb but did not replace any parts. Can't find any parts listed actually.
Haven't even been able to deduce how to get at the fuel line filter OR even if this Thing has one.
Help!

[ryobi_uk_warrenty_repair_centre]

if the carb settings are wrong the exhaust fumes are to hot
and sometimes melt the fan into the blower housing
this will make it tight and want to stall all the time