Well, I still aint sure what the difference between the two gaskets do but I can tell you that I had to make my round hole into a banana shape.
I had been through this card before, with a kit. The gasket that came out of it had a round hole, so a round hole went back into it. That was probably a year ago. I never could get it to run right. I even went and decked the two carb halves to make sure they were flat. Still couldnt get it set right. I then made a thicker gasket, with a round hole. Still no joy with that setup either. The D200 came into my world and I stopped working on the D160 that this carb was on. The D200 busted an axle bearing the other week, so I decided it would be quicker to get the 160 up and running so I could mow. I had purchased a Nikki card to use on the 160 so I made an adapter plate for it but before I switched over to the nikki I decided to try the DD one more time. Thats when I started this thread. I figured I had nothing to loose so I expanded the hole into the banana shape and reinstalled everything. I set the adjustment screws and after a minute of cranking she fired up. A few adjustments and I was off and running. I changed out the fuel line and filter and had to make one small adjustment on the main jet while I was actually mowing. She ran great the and I mowed my yard with it, about and hour.