Hi! I'm new here and this is my first post. Earlier this year, I bought an Al-ko string trimmer. After using it just a few times, the starter cord pulled out and didn't retract. The actual mechanism had melted! Sent it back for repair, and waited 5 weeks to get it back, and they replaced the mechanism. The same thing has just happened again! I'm using the correct petrol/oil ratio, which is 50:1, so I don't understand why it's getting so hot that it's melting the starter cord mechanism. Any help please?