the light on the gauge that is flashing is a ctually a FI light, which is short for Fuel Injetion. this light flashing after the unit is started means there is a problem with one of the sensors in the fuel injection circuit that is bad or had a poor connection.
before you start the atv, the light will flash, so you know the light actually works. after you start the bike, then the light is supposed to go off. when you turn on the atv, does the light continue to flash?
if yes, then there is a problem with one of the components in the fuel circuit. this circuit consists of fuel injectors, fuel pump, intake air pressure, intake temp sensor, engine temp sensor, throttle sensor, and a few more.
what is the year of your brute force? there should be a small connector near the battery with a connector on it that goes nowhere. that connector is a system to read the problem code you are having.
you will need to take the bike to a dealer to plug the jumper into that connector and tell what the code is. the code will pin point the problem sensor or component, then it will be checked and make sure the connection is good. the sensor can be checked two ways, to make sure it has power, ground, and then to make sure it is giving a good signal to the ECU. this is why the FI light is on, because one of the sensors is not giving the ECU the signal is needs.
that is a chance that is the problem
first, lets test the battery. any shop or auto parts store will load test the battery for free, and that will eliminate the any issues with the battery. a load test will put a load on the battery, simulating a starter, and read the voltage. the battery needs to have at least 10 volts for 7 seconds, and needs to do it twice. if the battery is good, then there is something wrong with the fuel pump(maybe)
if the battery is bad, it can trigger a FI light because battery voltage is below thresholdm or below needed voltage to run the fuel injection system.
you need a multimeter to test the voltage going to the fuel pump. if you get at least 10 or more volts to the fuel pump, and it is not working, then that is your fault code. a bad not working fuel pump will trigger a FI light. if the fuel pump is clogged, but still running, it will not trigger a code. with a multimeter, on volts DC in the under 20v range(if it is not autoranging) with the key and on switch on you should get the battery voltage at the fuel pump.
if you do and the pump is not working that is the bad part.
if you get 0 volts or low volts, then the fuel pump relay might be at fault, and is causing a problem sending the right voltage through the relay.
test the battery first, then the voltage at the fuel pump next
so the fuel pump dies or the engine dies because of the fuel pump?
and when it is running the FI light is on, right?
so there is another problem with the FI system. near the battery is the harness for the diagnostic port. when you connect the diagnostic connector, the gauge will flash a code, which will tell us which component is the faulty one(s)
the next step is to have a dealer plug in the diag port and tell you what the code is. you have to use the diagnostic connector, or damage to the ECU can occur. once we know what sensor or component is bad, we can simply change it out and fix the bike