My Honda NX 650 has been flawless since I bought it - I store it with the gas tank open to keep wet gas in the carb, and never had a problem with it.

And yes, 650's are monsters that you can get into trouble with I had an '83 XL600 when I was 18, and crashed it twice. Then I flipped the 650 a few years ago too...

I re-geared it for more low-end (topped out around 85 or so on the highway stock) and it's a real stump-climber now.