Hi I have the Stihl FS300 brushcutter & require a carb for it. I believe I need part Zama C1Q-S51C, which I believe is part number: 4134-120-0651. My question is does this come with gaskets as well if not can I buy these?

There are 4 different carbs listed for your machine. I have had a look and the part number you have supplied (4134-120-0651) is listed for your machine but it does not come with the gaskets. These are the ones you would need: https://www.lsengineers.co.uk/gasket-stihl-part-no-4128-129-0900.html https://www.lsengineers.co.uk/gasket-stihl-part-no-4134-129-0900.html