Flat tracking with the Yamaha MT-07 DT 750 cc twin

What began as an in-house project for Yamaha Motors US (YMUS) has ended a 30-year winning draught with the Yamaha MT-07 DT. If you don’t recognise the model designation from Yamaha’s catalogue, don’t worry, it’s a dirt track racing machine that’s custom built using the Yamaha MT-07 – priced at RM38,288 in Malaysia – engine as a basis.

Flat-tracking is a quintessentially American sport that, although has fans in other countries, has its primary fan base in the US. Born out of racing motorcycles on horse racing tracks, flat tracking involves the bike going left around an oval measuring between 400 metres and 1,600 metres.

For the MT-07 DT, the standard MT-07’s 689 cc, Crossplane parallel-twin is bored out to 750 cc. Little about the engine is stock, save the outer engine cases and Tommy Hayden – elder brother to the late 2006 MotoGP world champion Nicky Hayden – who leads the MT-07 DT project for Estenson Racing Team says, “it starts off as a production engine, but there’s very little production about it when we get finished with it.”

A head was developed with motorcycle performance tuners Vance and Hines, with cams by Web Cam and velocity stacks designed by YMUS. While it is usual for flat track racers to use air filter pods stuck on the inlet trumpets, the MT-07 DT has a custom built air box by YMUS.

“One of my main objectives was I wanted the bike to have a real air box, not just a K&N stuck on the back of the throttle bodies,” says YMUS Racing Division manager Keith McCarty. McCarty is also responsible for the custom-built MT-07 DT racing frame after an initial design from C&J in California did not work out.

“It didn’t turn out like what I was looking for,” McCarty says. “We didn’t want it to be just a Yamaha engine in a C&J frame, or look like any of the other models that they build. I wanted something more relevant and more modern in its design. That kind of got me going on doing our own frame.”

“We took it out for several tests, had a variety of different guys ride it and got some pretty good results right off the bat,” says McCarty. Taking it to the next level, McCarty got fabricators Southland to make some frames to be used for racing and possible sale to other flat track racers.

Tim Estenson of Estenson Racing Team steps into the picture at this point, after two seasons racing Yamaha flat trackers. Looking for a better chassis, Estenson and McCarty do a deal where Estenson takes the MT-07 DT and develops it further.

This led to Estenson Racing’s rider J D Beach winning – Yamaha’s first in premier class flat tracking in 30 years – in the Super TT class in American Flat Track at Chandler, Arizona. Followed by a MT-07 DT one-two by Beach and Jake Johnson at the Buffalo Chip TT with Johnson also took an earlier class win at Daytona.

“Racing is racing, whether it’s a superbike or a flat track bike,” McCarty says. “They have a lot of similar problems. You always hear the word traction wherever you go.” “Suspension plays a role. Every component on the bike plays a role. But all of the engineering things are not unique to just superbike or flat track. They all have the same things going on,” he said.

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