I've got a 2120 also. If I'm going to be on it for long, I wear some hearing protection. Maybe I'm imagining it, but part of what I hear is exhaust, but it seems like a lot is coming from the engine itself. It's got 1500 hours on it, and the valves have never been adjusted. I just had it at the dealers 2 months ago for clutch replacement, and mentioned the valves to them, and they didn't think they needed it (they didn't check them). I'm wondering if the valves do need adjusting, would that make a difference in the noise level. Has anyone done it and did it make a difference?