Fuel problem

[Ozarks]

701 normal mods
If I blow into the fuel tank it runs great, for 15 min.
Where should I start?
Fuel pump?
Reeds?
Carb?
Thanks

 

[fx1mark]

Fuel tank check valve. Then the screen filter in the fuel pump.

 

[Ozarks]

Thanks Mark, I went ahead and ordered, the rebuild kits just incase.