Motorcycle Questions? Ask a Mechanic.
Hi and welcome to the site, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.
Initially, the only easy user doable attempt would be to vigorously rock the Outlander left and right. The idea is to jar loose the float sensor of the gas gauge.
All others would be internal/electrical and would require the use of a multi-meter and possibly even a pull down of the gas gauge sensor.