While you wait for answers, we may have found some information which could help you.
Click here for Cutting Hard Start2 Stroke strimmer not running?
How can I fix my weedeater?
Mcculloch 2818 Runs fine but spool will not spin?
How do i keep my strimmer running?
Where can I buy a strimmer spool spring for my McCulloch MT270X strimmer?
how to change mcculloch sl trim head?