The "yellow" terminal is a 10-12ga. Not just a 12ga. 12ga is blue. Measure the opening of the terminal block, and look around for the correct terminal. Don't think you need 8ga for a SS 200 though. 10ga will work fine. Now, if you want to go at it a different route, just fit a 10ga wire into the terminals you have and squeeze the fork a little. Will shrink the fork slightly. Just enough to barely fit. Then remove the yellow nylon and add some shrink. Would look a little nicer too. Then another route is to barely trim the sides of the connector with a bench grinder... Or you can go with the 1st suggestion which is to look around for the correct connection...