I have a 6.5 hp Toro, it has been sitting for a long time, it will start but then cut out after about 10 seconds. The only way it starts is by priming it. I took the bolt off the fuel bowl and gas came out with a steady strem. Do you think I need to remove the bowl and clean? The mower was empty of fuel, I think it probably evaporated

Sounds like you have an extremely dirty fuel system. You'll have to take apart the carb and flush all of the fuel hoses and gas tank.

Kiss is correct, is suspect that you will find that the carb bowl has gum, water, rust, or trash in the bowl.