First time I had a plug and play carburetor that actually worked like this. Plug it in and it worked the first time and didn't need to do anything other than adjust the idle a bit. Since then it works fine. It was a transition from a Rochester 2 Dolly to this Holley 2300 350cfm and it required an adapter plate and was a real improvement on my 225 cu. in the Dodge Slant Six. Added a manual choke kit but started without it even in cold weather, just a few pulls on the throttle and it fires right up and runs until it warms up. I love this facility!