First off, how do you know it's running hot? I can't remember if your bike is air or water cooled, for some reason I think it's water cooled. If it is, are you going by the temperature gauge reading? Is the radiator full of coolant and have you "burped" it to expell the air? Does the fan come on? Is the radiator clogged up with mud, bugs or crud? Have you changed the coolant within the last few years? Sometimes old dirty coolant doesn't cool like it should.
The thermostat could be shot, the radiator could have scale on the inside, the temperature sensor could be bad, the impeller could be loose on the waterpump shaft to name a few things.
Low oil will make an air cooled engine run hot, but not a watercooled engine. The plugs wouldn't have anything to do with it. I suggest you check the easiest, most obvious things first and go from there.
