Chainsaws

I have purchased 2 PoulanPro PP4218AVX Cahinsaws. One is about 13 months old and it will not start when it is hot. I push the primer bulb and nothing is sucked into the carb and all it does is pressurize the tank. I was told that I needed a new carb. So I bought one. No help. I went to Lowes and purchased a new PP4218AVX a month ago because I need a chainsaw at the house. Now this one does the same thing. Both units do the same thing and now I have two units that I cannot use. The nearest service center to me is over a two hour drive. Any Ideas? This was purchased for home use.