Can't diagnose smoking ex

I took my EX out to the dunes this weekend. It ran fine for the most part. It didn't cut out anywhere or bog. Plenty of power was on tap to climb the big dunes riding double. When I would let it sit and idle after about a minute I would get blue smoke. I havn't checked oil level yet but it only did so on my last ride. This is a fairly fresh motor with only about 20 or so hours on it. I was running strait race gas and I am thinking it was a touch rich and carboning up the plug after idleing for too long, but that should smoke black not blue. I am at a loss at the moment as to what to think till I actully get time to work on it. Any idea's??

it might be a leaking valve seal.