"I have known Billy for a long time and he started with Yamaha back in his GP days, racing for Steve Dixon in Europe," said Coppins.
"He will ride all four rounds of the New Zealand Motocross Championships for us, hopefully winning the MX1 title here and then going on to race the Australian Motocross Championships later in the year."
Injury forced Mackenzie to the sidelines in the Australian Motocross Championships last season, but he has fully recovered and Coppins has faith in his new recruit.
"I know he will battle well against the likes of Tauranga's [defending New Zealand MX1 champion] Ben Townley (Carlton Dry Honda CRF450) and Mount Maunganui's Cody Cooper (Moto City Suzuki RM-Z450)."
Australian hot-shots Todd Waters and Kirk Gibbs, both riding for KTM Australia, will also add an international flavour to the series.
"Billy Mackenzie is one of the fastest starters in the world and can get out of the gate and simply check out. He is an awesome rider and hopefully he'll win a few races in New Zealand this year."
The four-round series kicks off near Timaru on February 10, with rounds to follow at Patetonga on February 24, Pukekohe on March 10 and Taupo on March 31.
Mackenzie will stay at the Yamaha Motor New Zealand training facility at Motueka for the first two rounds and then return to Australia, flying back to contest the second half of the series.
He is joined on the JCR Yamaha Racing Team by 28-year-old Queenstown rider Scotty Columb, racing a Yamaha YZ250F in the MX2 class this season.
Said Coppins, "With Billy in the team and Scotty riding as well as he is at the moment, it is an exciting time for me and for Yamaha. I believe we can win both New Zealand titles."
Mackenzie may have his work cut out to match Townley and Cooper, and Columb will be pressed to beat defending MX2 champion Darryll King (Yamaha), of Hamilton, and riders such as Waitakere's Ethan Martens (Yamaha), Mangakino's Kayne Lamont (KTM), Taupo's Cam Dillon (Honda), Mt Maunganui's Rhys Carter (Suzuki) and Tauranga's Peter Broxholme (Honda).
Whatever the outcome, it looks set to be an exciting national series.