I was at the dealer asking about an oil change and was told the valves should be adjusted on my 2011 550 TRV. The machine only has approx. 250 km on it. I'm just wondering if this is necessary as it starts and runs properly. Also he suggested I change the diff. oil. It's probably not a bad idea, but why spend money if it's not required? The machine is stored inside and has never been abused. I don't really want to fix what isn't broken.