any petrol flymo experts?

[nev]

Trying to get it to run 'cleanly'.
***Turning the air mixture screw in or out does nothing!****
its at 1 1/2 turns out, the fan operated throttle moves fine. air filters clean, as is petrol. new plug. starts a treat - no effort involved . choke functions as it should. cleaned underneath and sharpened blade.
Its an old L470 , and i cannot get it to run 'cleanly'? its usable but doesnt quite reach 'full throttle' and run smoothly.
I suspect its probably sh*t in the carb but before i strip it again anything worth checking?
any 'usuals' from any pros?

muchly thanked in advance.
nev

 

[RogerS]

When I had a problem with my petrol strimmer I took it down the local builders merchants where they have a repair centre and for £8 they gave it an ultrasonic clean up and now it works a treat.