I posted a question on this forum a week or two ago about a new HRX217 that was surging at start up - the mower would hunt up and down around the idle point for 20-30 seconds until it settled down, and I wanted to see if this was a problem. A reply from a long time forum user told me that he had recently purchased an HRX217 himself and his mower did the same thing for the first time or two he started it. He suggested I give it a few days and see if it wouldn't quit doing that. I decided to do just that and - lo and behold! - my mower stopped doing it, too. Runs like a top with a rock solid idle that settles down within a second or two, now. And I thought it might be useful to someone else to post this here, in case they buy an HRX217 and it does the same thing.