Honda's 2012 prototype World Motocross contender broke cover in Japan last week.

The Honda World Motocross Team has debuted what could be a pre-production version of the 2013 model Honda CRF450R motocross bike.

Officially labeled the 2012 factory bike by Honda, the race team of Rui Gonçalves and Evgeny Bobryshev will develop a new-look prototype Open class bike from Honda next season in the world championship.

Debuting the bike at Sugo’s round of the Japanese Motocross Championship last weekend, with Gonçalves winning ahead of Bobryshev overall on Sunday.

“It feels good to take the win on my first outing with the new bike,” Gonçalves said. “We are all working really hard out here to evaluate the new package and so far things are going really well.”

Bobryshev agreed that the new bike is already a positive step forward for next season.

“It was real important to test the new bike and we are all really happy with what we have – it is something special,” he added. “Over the next few days we will learn even more about it.”

The Sugo race came at the beginning of a five-day testing program in Japan for the Honda World Motocross Team. Engineers from the team are working in close unison with engineers from Honda Japan as they evaluate the prototype factory bike.

Initial images indicate much of the updates are based around the motor, with the exhaust port now exiting the right-hand side of the cylinder before the pipe wraps around the left side of the engine and the sweeps back to the right behind the cylinder.

Other notable items spotted on the factory prototype model include a hydraulic clutch, used by both Gonçalves and Bobryshev.

To see detailed images of the bikes, check out this link.

Honda is yet to confirm whether these changes will be incorporated on the production model for 2013.