McKenzie's round, the lowest of the day, was only one shot off the course record. His two-round total of 134 is two behind the leader, the American Ron Whittaker, who is playing in only his 10th professional tournament.
Whittaker shot an eight-under-par round of 64 to add to his first-round total of 68. Zimbabwe's Tony Johnstone is third after a four-under-par 68 for a two-round total of 136.
Britain's Chris Davison and Michael Archer, who were among the first-round leaders, both shot second-round 74s.
n A hole in one with a six-iron on the 163-yard, par-three 17th hole enabled Barb Mucha, of the United States, to snatch a one-stroke lead after a first-round 68 at the LPGA Tournament of Champions in Orlando, Florida.
Beth Daniel was second and Betsy King and Tammie Green third on 71, with Britain's LPGA champion, Laura Davies, and the defending champion, Dottie Mochrie, fifth on 72.Reuse content