07 TRX450R - rough idle

[stampern]

Hey guys, I just picked up a 07 TRX450ER - the black one with the red frame. It runs pretty good. It sounds funny to me when it idles, really rough - almost sounds like it's knocking. It's also a little boggy off the throttle - once I get back 1/3 throttle or so it opens up and I can't keep traction through 4th gear (love it). The guy I got it from didn't use it much and it was bought in Florence OR, so it was originally tuned for sea level. When I had it at my dads house (1300ft roughly it was running like this). I'm in Boise ID now and it's running a little better but I'm at 2700ft now. The guy I bought it from lives around 2300ft. Can the wrong jet/tune cause it to knock that bad? I'm also curious what this is going to do when I go to Dune Fest in Aug.

First thing I'm going to do is do an oil change and run some nice honda partial sythetic in it and also kick up the octane - it might be running lower octane right now - not sure - haven't even gone through a tank in it yet.

Any info would be greatly appreciated.