Rough idle and stalls hard to restart

With no test results or other observations to analyze, your description sounds like what happens when the pickup screen in the gas tank is collapsing or plugged. Typically the engine runs fine for five to fifteen miles, then when it acts up, it runs okay at highway speeds, but the stalling occurs when the largest volume of fuel is being pumped, which is during coasting. The screen will stretch out again after about ten minutes, then the engine will run for another mile or two. This only applies to engines that have the fuel pressure regulator on the engine, and a fuel return line to the gas tank. You did not list the right engine size so I cannot look up which fuel system you have.

The strainer can be purchased separately for about ten bucks. It snaps onto the fuel pump assembly inside the tank.