The American, chasing his first PGA Tour title after six second-place showings in two years, stood on 13-under 129 after 36 holes at TPC Deere Run in Silvis, Illinois.
"Nice to have two really good days to start the tournament," Young said.
Young, a runner-up most recently in March's WGC Match Play, has as many runner-up showings without a victory as any player in the past 40 years.
"It's really just a 'one foot in front of the other' kind of thing, executing the plan we've made for the week," Young said of chasing his first triumph.
"If I can control my mind and stay in some control of my golf ball, hopefully I'll give myself a chance in a couple of days."
South Africa's Garrick Higgo and Americans Adam Schenk and Brendon Todd shared second on 131. Sweden's Ludvig Aberg was on 132 with Americans Denny McCarthy, William Mouw and Kevin Roy.
World number 19 Young credited work on his putting with his successful start.
"Made a few mechanical changes, just really the tempo, and I think it's helping me control my speed a lot better, which is leading to some better green reading," Young said.
"I'm seeing good signs. Even the ones that don't go in, I feel like my speed has been really good and I've been rolling it how I mean to -- I've been able to take a little more confidence."
Young opened with a four-foot birdie putt at the 10th, chipped in from 29 feet at 11 and sank a birdie putt from just inside 10 feet at the par-3 12th. He added birdie putts from about eight feet at the 15th and par-5 17th.
He blasted out of a greenside bunker within inches of the hole at the par-5 second and tapped in for birdie.
After finding a fairway bunker and making his lone bogey at the fifth, Young sank a 20-foot birdie putt at the par-3 seventh and closed with a five-foot birdie putt at the ninth.
Back-nine starter Higgo, who shot 66, opened with an eagle and closed with a bogey to fall two adrift.
"I'll just keep doing what I'm doing. I'm not going to change much," Higgo said. "It's good momentum going into the next couple weeks."
US back-nine starter Jim Herman reeled off seven consecutive birdies from the par-3 16th through the par-4 fourth holes on his way to a 63 to share 10th on 134.
Sweden's Jonas Blixt, who led after an opening 62, followed with a 73.
