i have a mc culloch string trimmer silver eagle 28 and need to know how to adjust low and high needle screws,starts intermitantly and will only run at full throttle choke open,i adjusted the screws and then found out that the spark arrester was plugged,any help appreciated

rt10 teddy, May 2010

start by turning both screws all the way in not to tight but snug then turn both screws one and one quarter turns out start your trimmer atjust shy of full throttel adjust the high idle until it sounds like it is running on straight gas then turn it back about a quarter turn stay on the throttel until u r ready to adjust low idle back off on throtrtel until it wants to die and adjust low screw most likly turning clockwise when it is running better let off the throttel again and repeat until it runs at idle note you may have to adjust idle screw also

ron maury, June 2010