You are not suppose to mix the gas in your tank, most kits say that is a no no you could be right out of gas or close pour it in all the oil hose to the carb bowl and gas line very little left over any eqausion.
Also you may have half a 5ank of gas left it's going to be crazy f*** up on adjusting values.
Make it easy on your arithmatic brain function get a 1 gallon DOT approved container use what ever it stars on the oil container but 64.1 is way to lean you'll burn your motor leanest I would ever go is 32.1gallon, 25.1 gallon not bad either.
Just fill your tank every morning before you ake off
I don't like mixing in and storing gas, nor do I like gassing up every day.
I had a gallon tank on my last bike. My Tanaka engine averaged 66mpg, enough for 5 days' rides to work.
I knew when my tank was half-full or less.
I'd go to the gas pump, add a quart of gas, then pour my pre-measured oil in, and pump another quart in.
The major sloshing from the gas nozzle was enough to mix the gas.
My engine never protested.