My K1100lt stays just at the edge of the red for temp.
Where should my gauge be staying while riding? At the edge of red even during cool mornings.

Not really, i would expect it to be mid green. ideally. you dont say if fan kicks in or temp light comes on so i would check coolant mix, test thermostat, just to be sure.
PS worth testing temp gauge as well

Fan does come on, no temp light. I just don't remember
seeing it run this hot. Is there an ohm test for the gauge?

On my bikes, the BMW temperature gauge needle stays around the 11 o'clock position when moving.  When stuck in traffic it will go to the 1 o'clock position.  About half way from there to the red the fan will come on and the temperature will come down to the needle at the 12 o'clock position.

If your gauge is reading high, are you sure the engine isn't overheating.  The cooling system on K bikes can be a little marginal in hot weather.  If the passages in the radiator are coated with mineral deposits from a previous owner who filled the system with well water or the fins are full of bugs, the radiator's cooling efficiency will be reduced.  It's also possible that the thermostat isn't fully closing off the radiator bypass when the engine comes up to operating temperature.

Two years ago I replaced the thermostat and coolant. Just as a preventative.

Might be a good idea to do a cooling system flush ,and ditto on #4 with cleaning bugs out.
One other thing , Check the hose from RAD to HEADER TANK for blockage or kinks

Thanks for the replies.
Summer has kept me to busy for trouble shooting.
I did ride through a rain storm last week and the temp dropped quickly below to halfway mark.
I will start with flushing the system and check the hoses.
Thanks

Just remember that the sensor for the temperature gauge is under the water pump and only serves the gauge and nothing else.

The cooling fan and temperature warning light are fed from the temperature sensor behind the radiator which also feeds into the Motronic unit. This one appears to be working properly as fan comes on and red warning light does not. It only comes on if the engine over heats.

The fan comes on when the temp of the coolant coming out of the cylinder head reaches 105C (221F).

The temp warm lamp illuminates at 115C(239F).

If you keep riding and the temp reaches 120C(248F) then the radiator cap will blow (just like an overheating car.)  It gets on your left foot.

It is rumored that the Motronic will shut down somewhere above 120C but I've never felt that risking destroying engine was worth it to to test that.