My Craftsman riding mower recently started having problems. It ran fine all last season (purchased used last September), however, the past 5 times I have mown, it will run fine for about 15-30 minutes, then will be starved for fuel. At startup of mowing there is fuel in the in line filter, however, when it dies, there is not. After letting it sit for about 20-30 minutes fuel seeps back into the filter and it will start again, but only so long as fuel remains in the filter. It has been dying multiple times per use, making it hard to get my large yard finished. I have a new in line filter I am planning to install to see if that could be the problem, but was wanting to get some opinions first. I have tried taking off the gas cap to make sure it's not vapor locked, however, that doesn't make a difference and it will not start up even then. Thanks!