Do you know what kind of tail light fits a 04 honda sport trax 400Ex and lights up when you hit the break? (where could I get one and only a bulb not the hole light)

 

There were times not so long ago that ATVs just had "running lights" and no brake lights...my 1994 TRX300EX just had a rear light, with no indication that I was hitting the brakes.

Tprender nailed it...Honda won't spend a dime to make it better once it's been designed...for example the aforementioned 300EX...almost 20 years of production on the same design. QUAD, theres your answer as well, you'll have to wire a brake light system into the bike, and even if you can find a bulb that fits the stock light socket, it will still be missing the additional contact to light the bulb. Maybe getting a light assembly of another brand and then wiring it into the 400 is the best/easiest way to get a brake light.

Murphy, the actual phrase is from Benjamin Franklin, who said, "It is better to be thought a fool than to open your mouth and remove all doubt." I try to keep my mouth shut as much as possible...lol