If it has been sitting that long, you will end up needing to clean the entire fuel system imo. I bought an ltr that had been sitting as well, but not 3 years. I had to clean the fuel system and end up getting a new injector. Gas gums up over time in the lines. Just draining will not clean it. Also the ltr has 3 filters, swirl tank filter under the gas tank, one in the injector itself, and one in the fuel pump. You will want to clean all 3 imo.
I deleted the swirl tank filter as it gets nasty on ltr's. Then put an inline fuel filter going from tank to fuel pump that will save a lot of headaches in the future.
Start with cleaning the fuel system and see how it goes. Is the ltr sputtering, popping, show loss of power? If so it is the fuel system.
Other small maintenance issues might arise soon after you get the fuel issue fixed. It is not good for a quad to sit for long periods of time. I have had to replace clutch cable, clutch kit, and other small items like that since I bought mine.
BTW make sure you have a fresh new battery, if it is the original or old battery it will give you issues later on.
White Bros Slip on
K&N Jet kit
Tusk Front Brush Guard
Razr / Sti tech 4 XC tires and STI sport alloy wheels
LTR450 - cherry bomb, nerf bars, razr mx tires, baffles removed, pro elite grab bar and a couple more goodies for now..
Rotella T6 goes in all my toys