'I played under control,' said Weibring. 'I feel like I've got another good round in me but who knows what'll happen.'
Tom Watson also posted a 68 at Glen Oaks Country Club to join Tom Kite and Tom Jenkins in a tie for third at 5-under-par 137. Joe Inman and Bobby Lincoln were one shot further back at 4-under-par 138.
Weibring, who won at the SAS Championship in his rookie season on the Champions Tour last year, picked up where he left off from the opening round with a birdie at the par-3 second. He stumbled soon after, however, with his first bogey of the tournament at the par-4 fourth.
The 50-year-old came back with a birdie at the par-4 sixth and hit his second shot to 22 feet at the par-5 ninth. Weibring then took two putts for another birdie to make the turn at 8 under.
At the par-3 14th, Weibring dropped his tee shot off a mound and watched as it rolled within a few feet of the cup. He tapped in for birdie to hold onto the lead with one round to play.
'I played pretty well today,' said Weibring. 'I felt like I played a smart round. This is a good course -- if you don't play well, it'll getcha. I'm looking forward to tomorrow.'
Walzel, who is seeking his first career victory on the Champions Tour, tallied back-to-back birdies starting at the par-4 fourth and added another birdie at the ninth.
The 54-year-old drained a 30-footer for a birdie at the par-4 12th, but missed the green with his second shot to the par-5 15th.
Walzel, who has dealt with multiple injuries over the last few years, hit a remarkable chip that rolled within 5 feet of the hole and converted the birdie try en route to a round of 66.
'It'll be the height of anxiety for me tomorrow,' said Walzel, who stands at 8-under-par 134. 'I'll be nervous starting out but that's okay. I'm just going to enjoy the day and hope for the best.'
Watson mixed three birdies and a bogey on the front nine before finding trouble with a bogey at the 10th. He countered with a birdie at the 13th and ran home an 18-foot putt for a birdie at the last for his share of third.