Have a red and black warrior. Square headlights down by front guard. Serial number ends in 84. Is this 1984 model?

 

To early I think to be a 1984, the first ATV was made by Suzuki in 1983 and it was only a 125. I think the Warrior first year was 1987 and was discontinued in 2004.

By this site it sounds like a 1987 Yamaha ATV History looks like Yamahas first ATV was just a converted 200cc 3wheeler with a extra front wheel added on in 1985.

 

Red and black, square headlights is going to be a first year machine if the plastics are stock. The Warrior was introduced summer of '86 as an '87 model. You can look up a vin decoder online to get the actual model year.

 

That does look unique with the two square headlights mounted low. Most all have two round headlights mounted higher up.

 

Moving the headlights was one of the few changes made to that model, up to and including the newer Raptor 350s. Hard to believe that same quad you pictured above used to get my pulse pounding as a teenager

 

That's a long run for a ATV model 1987-2004 and even when the 350 Warrior was replaced by the 350 Raptor they still have the same motor and very similar specs.
1999 Yamaha Warrior ATVs even used the same carb, gas tank and front suspension.

When I was a teen a 350 4x4 Foreman or Big Bear was considered a big bore Mud beast.