I aquired the GXJS40A Mower which does not look as if has not been used much. The carburetor has been taken off of the mower then replaced. I removed and cleaned the carburetor and installed it with a new choke bulb and it would not start. I noticed one thing that their is a spacer between the carb and intake on the head with groves on one side of the spacer and slick on the other side, where should the groves be, next to the carb or next to the intake. I would appreciate any info or suggestions.