The second thing I would do is test/replace the radiator cap. If it's not opening/releasing pressure as you ride, the temp will increase. But you said it was only about 40degrees outside when you were riding? Maybe you have an improper map on your power commander causing the bike to run to lean? That could elevate temps.
Or you could have a faulty thermostat. (Although my experience has been that they normally stick open, not closed)
If the thermostat is faulty, you can do a bit of a visual check. Starting with the bike completely cold, remove the right fairing, bike leaning on sidestand. Remove the radiator cap, start the bike and let it warm up. Watch the fluid in the radiator, it should be pretty still until the temp reaches about 172F. Then you should see the coolant swirling in the rad. That means the thermostat is open. Now that it's circulating, continue to run the bike and watch the temparture. Snap the throttle a couple times - as per the Service Manual - You may even see some bubbles burb out of the radiator. If that happens, that could be part or all of the problem.
I don't expect the bike should warm up more than about 190. if it does than I suspect circulation problems. The coolant should be swirling pretty good in the radiator: if it's not, that means,
1. Thermostat may be stuck closed. Check ALL hoses and clamps, make sure the smaller hoses, like the overflow hose that goes from the rad to the overflow bottle, are flowing.
2. Waterpump may be failing. Look closely at the waterpump inspection hose. There should be zero sign of leakage. If there is, you could have a waterpump bearing going out.
Section 6 of the Service Manual details everything I just went over.
John, 2000 RC51 #000100