I recently bought a 1981 gn400 from one of my neighbors. The bike is pretty complete except carburetor is missing. When I Google want to buy a carburetor for a 1981 GM 400 about 50 pop up I know not all these carburetors fit my 396 cm3. It doesn't have to be a Mikuni I want to make sure everything else is good before I spend a lot of money on the bike. Which aftermarket carburetors do I buy?