Racer 450 Magazine
1350cc Shootout
January, 2007

ENGINES:
For 2007 Honda stuck to their guns with the same power plant they released in 2006. That power plant brought the 450R to life and evened out the field between Honda and Yamaha. Although not a one off of the CRF450 the engine does finally share the same bore and stroke as well as some other inner parts. A high compression piston also brings things to life. Honda swapped out for a new gear ratio in the 06/07 transmission. The old gear setup was a love it or hate it package. We loved it but we have to say that the new setup really is much easier set up for different tracks. Good going for Honda. This is a great engine and we actually consider it better than having a dirt bike motor in an ATV chassis. The 06/07 engine is far superior to that of the 2004 and 2005 models, there is enough power here to challenge any production ATV on the track and it’s all useable. Kudos.

Yamaha stuck to their guns as well in 07 but did manage to include a piston oiler. The engine has been set up for this since day one of production and we can’t believe that it took this long to get it. We are very happy it’s there and it should extend the engine life for those hardcore race guys as well as the guys who fail to do proper maintenance or ride their YFZ in the mud constantly. 06 updates that carry over for 2007 are the extended stroke crankshaft that actually makes this a 450 (2004/2005 models were a 440), as well as the cam and porting changes. The Yamaha actually does have a really good trans setup with gearing that is pretty close to perfect with the stock tires. Once again, good job Yamaha. The 5 valve twin cam Yamaha engine keeps getting smoother and smoother becoming more rider friendly as well as gaining more power each year. We’re sold.

What can we say here? Everything is new. This isn’t Suzuki’s 450cc dirt bike engine. It was developed exclusively for this ATV. It has fuel injection and more onboard electronics than you can load in a Mack truck. How does it run? It screams; it has good power everywhere. On our initial tests we had severe hesitation problems and inconsistent performance. What did we fix? Nothing, somewhere along the way to being broken in these problems mysteriously fixed themselves. The engine runs and performs excellent now. Does that make us happy? No, we really don’t understand the problem and would prefer Suzuki’s dirt bike FCR carb any day. Will Suzuki change next year? Most likely not, they have simply put to much time and development into this fuel injection system to turn back. It is likely that over the next few years this system will begin to shine, especially after Yoshimura gives Suzuki R&D all the feedback from this year’s race season.

These machines really haven’t been out long enough for us to see the engine or electronics’ endurance or reliability. This for us could be the sole deciding factor for a purchase. Sensors, sensors, sensors…

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