Getting hard to start

[superduty]

Hi All,
For the last several days, my bike has gotten harder to start. Most of the time, it won't start till the second try. Turns over as briskly as ever, but doesn't fire till the second try. Maybe idles a little rougher than before, but no change in power when underway. Not sure what, if anything I should check, or maybe just take it to the dealer service.

It's been cooler and very humid here lately. I always gas-up at the same place and use 91 octane. I've also noticed pinging for the first time too. Hadn't had any pinging all summer. I've changed the oil about 400 miles ago, from OEM to Mobil 1, 20w50. Bike is a 2007, with 3500 miles on it. Stock pipes, filter etc.

Thanks.