Mccoulloch maccat 330 won't run?

I have checked the fuel mix, is ok..checked the pull cord tension and the spring, is ok. So why does the cord hang out loose after about 10 pulls (hard to start) and then when it does start it dies if I put full throttle on, (the cord retracts slightly when this happens).
It was serviced 2 years ago and only used 4 times since then with no problems. Help, i've had enough!!!! Is it me or is it just crap?