We have a 48 Volt 1800 Watt modification kit for Razor MX500, MX650, and SX500 dirt bikes without a battery pack or battery charger which would be a great fit for your project. The controller in this kit has an under Voltage protection shutoff rating of 37 Volts so it is designed to work with both lead-acid and lithium battery packs.
Here is a link the kits: https://cart.electricscooterparts.com/store/Search.aspx?searchTerms=razor+MX500+and+MX650+dirt+bike+modification+kit
Will there be any controller (or any other) issues with using a lithium battery setup with the modification kit you posted a link to?
I already have a 48v 22ah battery pack and charger that I'm planning on using
The test results in this forum post are relevant to the discontinued 48 Volt 1500 Watt 5300 RPM Boma brushless motor. We removed the links to the 1500 Watt 5300 RPM motor and replaced them with links to the 48 Volt 1800 Watt 4400 RPM motor. Please be aware the test results posted below will be close to but not the same when using the 48 Volt 1800 Watt 4400 RPM motor.
I posted elsewhere here that I had ordered the motor under a thread about hub motors. New thread for this.