How do you set the valves on a 1981 Honda atc 185s trike---T for timing mark or F for fire mark I have been told two different ways one set on timing mark then another on fire mark?

You're setting valve lash here. It shouldn't make any difference what mark it's on. You want the valve to close completely when the rocker comes up. With no more movement after that. Once you get one valve set, roll the engine over half way and set the other one.

Set valve lash on both valves with piston at top dead center, the T mark lined up with the mark. Valves should be set at .02 for that model. You do not have to roll the engine through to set the valves. but it is a good idea to roll it through 360 degrees after setting is complete and recheck the settings