my petrol strimmer only runs (briefly!) without!!! the carb!?

with the carb on my strimmer will not run, yet if i take the carb off it will run until the fuel runs out. the diaphram seems fine, i'm bemused, can you help?
em, March 2005


done
Might be a clogged air filter. Try with Carb without air filter.

Dan, April 2005