my strimmer keeps stalling when I open up the throttle?

after it has been running for while check the plug and see if it is oily or dry.
if oily check filter and clean thoroughly.
if dry then it could be getting to much air causing it to run weak.
check and post again with results?
may be able to give a better answer.
I've just repaired one with similar problem and found the bottom gasket (cylinder head) leaking, replaced it and runs fine now.

cg
September 2011

try cleaning the airfilter , and change the fule,put fresh fule in . and let it run for a wile before you give it full revs, and dont make the fule mix too strong..

m
August 2011