Purchased a kart help me identify it

[WillMatrix]

Wow, that's a loaded question. Firstly, my consistent answer about ratio changes is to advise starting with a sprocket carrier hub for the rear axle with quick-change (6 little bolts) 2-piece $15 split sprockets. Once the hub is on the axle, you never have to slide anything off the axle and back on again for a sprocket change. Secondly, your split sprocket to begin with should be the largest diameter you believe you'd possibly want, so any change to a smaller diameter will require removing links for the chain, not splicing little pieces into it.

This is a great start to some great information.
My problem is that I don’t find many split 40/420 sprockets. I’m going to upload some ideas and get your opinion

 

[madprofessor]

Forgot that only #35's are only $15. Here's the higher price from GPS for #40's in 42T-68T, but a lower price than I paid ebay for a hub...............
Split Sprocket #41/420 - GoPowerSports.com (42-68 tooth sprockets), and......... 1" Sprocket Carrier Sprocket Hub - GoPowerSports.com (1" hub).
Here's an even lower priced hub from OMB.................
Uni-Hub, Steel, Zinc-Plated, 1" Bore, 1/4" Keyway & Set Screws Only - OMBWarehouse.com
EDIT: Bonus of the standard 5.25" bolt circle carrier hub is the ability to add split guards, like the 4-piece (double-sided) in pics below.