Can anyone tell me if/what carb can be used to replace the C-13 carb? I have a near new FS-120S (4 tanks thru it) that appears either the pump has failed or the regulator has failed. I don't need the pump in my application so I just want to use muffler pressure can this be done? I don't want to spend a ton of money on this engine but being near new I think it would be worth trying a different carb. Thanks for any help!