My 900SL also runs at 110C on a longish run. What seems to happen is that after 10 miles it's up to temperature. Then if i'm running fast it goes up to 110C and doesn't seem to come down regardless of how I ride after that. Will go as high as 120C if it's in traffic but goes back to 110C after that. Strange. I was also worried about it at first but now it's just normal operation.
One thing to check is the oil cooler tap which is on the left hand side of the bike, towards the front, next to the oil rad. Not all bikes have it fitted. It's to transfer oil to the carb heater kit to prevent carb icing (apparently). In summer time it should be inline with the pipe. In winter mode - ie my carbs are cold - it should be turned 90 deg to the pipe. Might make a difference to the temp, might not.