The four-round New Zealand Motocross Championship begins this weekend with Bay of Plenty riders in contention in each of the three main classes.

Defending MX1 (450cc) champion Cody Cooper of Papamoa heads the MX1 field with his main opposition likely to come from international riders.

Australians Kirk Gibbs and Ford Dale will compete with the KTM team while Josh Coppins' Altherm Yamaha operation has Australia-based Scotsman Billy McKenzie returning for a second New Zealand campaign.

Cooper says he's well prepared for his title defence with his most recent success coming at the NZ International MX Grand Prix at Woodville in January.


"I got home from doing some testing in Australia the week after Woodville and that went well," said Cooper.

"I'm feeling good on the Honda and the plan is just to keep on doing what I've been doing.

Taupo's Brad Groombridge (Suzuki) has been the next best of Kiwis in early competition and Honda riders Michael Phillips (Rotorua) and former champion Justin McDonald (Christchurch) will be also be leading MX1 contenders while Kawasaki will field Dion Picard (Atiamuri) and Jesse Donnelly (Paraparaumu).

The MX2 (250cc) field again has the deepest line-up in terms of potential race winners.

Mount Maunganui's Rhys Carter is looking to step up from his third position in 2012 and 2013 as he leads Suzuki's challenge and Tauranga's Peter Broxholme (Honda) finished fifth last season.

Broxholme is one of the most experienced riders and is predicting the MX2 competition will be intense.

"MX1 is more international and MX2 is really where it's at in terms of New Zealand motocross talent," says Broxholme.

He identifies veteran Darryll King (Hamilton) and defending champion Scott Columb (Queenstown) - both on Yamahas - along with Honda's John Phillips (Rotorua) as likely contenders.

"And there are a few young guys coming through as well like Kayne Lamont [Husqvarna] and Hamish Dobbyn [KTM] on the 250cc 2-strokes. It's going to be a battle."

Yamaha will provide the international flavour in MX2 with Australian under-19 supercross champion Jay Wilson joining the field. Broxholme says he's looking to improve on his early season results.

The 125cc class features two teenage Bay of Plenty title contenders.

Yamaha's Logan Blackburn (Te Puke) finished a close second last year and the 19-year-old completed 2013 racing with success in the Australian series and winning the Youth MX class at the BOP Summercross event in December.

Omokoroa's Aaron Wiltshier announced his arrival in the senior ranks last year with third place at his first attempt in the senior nationals.

A former 50cc and 65cc junior national champ, Wiltshier, 17, rides a KTM and recently won the New Zealand MX Grand Prix at Woodville.

The four-round series starts this weekend at the South Canterbury Motorcycle Club track.