Where did you install the temp sensor for the temp guage? On my 07 RG it installs in an adapter that fits between the engine and oil filter. Oil temperature is sensed after it goes through the oil filter. If the oil filter filters oil before it goes into the engine then this oil should be cooler than oil coming from the engine. Maybe it doesn't matter. Just thinking...

 

Mine is crammed in the oil pan, the plug next to the oil drain plug.

 

There are numerous threads on this topic here. Search on "oil cooler pan" (no quotes and you should find plenty of info and testimonials. Basically, the HD solution for sender location is inane, and you're much better off buying a $2 adapter from Napa #3220 x 6 x 2 (1/8"F-3/8"M) and install the sender in the oil pan (Allen plug to the right of the drain plug).