I took the carb off the engine and checked the manifold gasket and case gasket. The case gasket was good, but the manifold gasket did not look to good so I replaced it. I also checked the reed valve for any wear. The reeds looked good. I went ahead and replaced the gas screen in the carb and used my aircompressure along with carb clearner to blow out all of the little gas channels in the carb. I have put everythibg back together and now well see what happens. My carb that came with the SV-26 is a Walbro 731 and it has a 9.55mm venturi. The WT-694 that Mr Bigg has on his SV-26 has a 12mm venturi. If this does not work I am going to try the WT-694 carb