I am using a Mega Mount. Looks ok but I don't know. I know the way you tighten it .makes a difference. I had forgot about turning the nuts up close up close and turning and tightening. I think I used to do that.
It looks lined up but I will check again. I just turned the axle over and moved the hub u tilt it looks like the sprocket is running in the center of the chain.
I just fought this on a new kart i bought. The front portion that sits on the frame of this mount didnt have notches in it to sit down between the frame rails. Every time you changed a gear or clutch it was a fight to get it back straight(lost more than i won). Buy a mega mount or something like that if you have an old mount like i just described.
I've found that the OD of the sprocket carrier, and the ID of the actual rocket, have a actual difference in measurements. There are tolerances you have to consider. If the tolerance on the carrier was too much, and didn't match the sprocket, then what. You always have tolerances when machining anything. I don't know what the tolerance is when machining sprockets and carriers, but you don't want the sprocket to small or the carrier to big.
If you test the tention on the chain, as you turn the axle, you'll see that in some spots the chain is looser than in other spots. I always turn the rear sprocket until the tension on the chain was the highest, then, using a 2 x 4 up against the rear of the sprocket, I would hit the 2 x 4 with a hammer. This always worked for me.
If the chain pulsates loose and tight then your rear gear is not running true. Sometimes you can loosen the sprocket bolts, find the tight spot and tap the chain/gear to move it. Most time there will be no play so you will have to use a round file and clean up the edges on the inside diameter of the sprocket until you have enough clearance to get it on center. This is the last thing to do after checking everything else.