EFI for Yamaha in 2010?
By TMX Archives on 9th Apr 09
YAMAHA is the only one of the Japanese Big Four currently without Electronic Fuel Injection (EFI) on at least one of its off-road bikes. But the word on the street is that they will bring something rather special in 2010. A friendly "No comment,” was all that Yamaha Motor Europe Racing Division manager, Laurens Klein Koerkamp, would offer directly on the subject, but he was quick to point out: "Yamaha has never followed trends simply for the sake of following trends. When we are satisfied that we can offer the customer a completely reliable solution, whether it be 2010, 2011 or 2012, then we will introduce fuel-injection on our off-road bikes.
"But let me remind you that David Philippaerts won the 2008 MX1 title on Yamaha and that Toni Cairoli was in contention for the MX2 title until he was injured. Our bikes are fully competitive without EFI.
"Yamaha was also the last of the Japanese manufacturers to introduce an aluminium frame but, when we did, it was the best. And the steel frame we were using prior to that was actually lighter than the aluminium frames of some of our competitors.”
The reason for secrecy is not hard to find, as Yamaha is poised to literally turn around all previous technology with its 2010 range. If rumour is to be believed, the inlet tract will be at the front of the engine and the exhaust at the rear!
The traditional positioning of various parts of a motorcycle engine has always been dictated by available space and the necessity for protection of vulnerable parts.
Gravity feed has meant that the fuel tank had to be placed above the carburettor and, while space was found for radiators at the front of the motorcycle when water-cooling was introduced, air-boxes have always been under the seat.
Aprilia has already reversed the traditional positions of fuel tank and air-box but the very fact of being a V-twin rules out the possibility of optimising such a switch. One of the by-products of the KTM/ WP PDS system has been the possibility to offset the shock mount on the swinging arm, thus allowing a direct airflow to the carburettor and a reversal of direction so that airflow comes from the front to optimise power has been successfully applied in road-racing with air scoops delivering the draught over the top of the radiator. And an airbox-mounted EFI unit behind the radiators is of course suitably protected.
Just how Yamaha has solved the potential problem of air-intakes becoming clogged up with mud is not clear, but the 2010 YZ is potentially a rocket!
The entire project throws up even more fascinating questions, for example the layout of the exhaust pipes, the reduction of noise in such a relatively short distance, and the effective use of weight distribution which a reversal of previous norms now permits.
But, as Laurens Klein Koerkamp remarks: "Yamaha has never followed trends simply for the sake of following trends,” and the introduction of the Tilkens monoshock on a Yamaha as long ago as 1973 revolutionised successful off-road design in that era...