Well, how much material did you remove? Dimention wise I assume you like most follow the wiki but I'm curious. The intake is pretty rough and still seems very small overall. Did you start with a 20mph cylinder perhaps? The intake itself should be much smoother than that. Not glass like smoothness but much smoother than what you have there. Also the opening should be matched to the intake you have mounted to it. You want the air to flow very smoothly so match the intake to the intake port. It's pretty easy to do with the benty intake but again smooth. Try using some rough sandpaper, a different cutting bit (I find a good dull but cuts smooth and doesn't cut very fast). Make sure you camfer the edges on the inside of the cylinder. You can do it with a file or very carefully with the dremel. And make sure you clean everything super well with qtips and dish soap. You don't want any of the powdeer in the engines parts. It may take a while but you can do it. And once it's done it's done so take your time with it. Also what is the rest of the setup if you don't mind.