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2/20/2010
Location
Sturgeon Bay, WI
US
Edited Date/Time
9/13/2020 8:37pm
After watching red bud , and pretty much all the star 250f riders were doing the larocco leap. What are they doing to get that extra power? Is it the reversed motor in the yamaha? And what are the other mfs going to do to match them?
The Shop
Last time I was at a dealership I looked at the Yamaha Front intake if that cylinder was turned around with the same exact intake set up and the rest of the motorcycle designed around it shock included to where the Herb ox was in the exact same location but drawing air from them back going in like a conventional setup could it not make the same kind of horsepower numbers? Or is it all about the foot intake just because of that reason?
or why it wasn't done prior.
If you watch MXGP those old kickstart Kawasakis are pretty much even with Factory KTM/Husky/Yamahas. There are not any real Factory Honda teams out now.
Dirty Points hit the nail on the head: it's an integrated design with obviously good detail work.
My opinion, the front intake setup is beneficial for power production but compromises the layout and ergonomics of the bike. Not a big deal on a 250F where power is king but doesn't appear to be helping the YZ450. And it's definitely not helping everyone who can't gel with the bikes just being too big.
I suspect in the future we will see other brands doing setups similar to what you see on road sport bikes. Essentially, swap the locations of the airbox and the tank. You can still have the intake in the rear of the head but you can make it very straight and downdraft by putting the throttle body and airbox on top of the engine and placing the tank back under the seat.
It’s more than just the engine. Any bike manufacturer or engine builder for that matter can make a 250 that fast. It’s more of a problem with reliability. Whatever is going on with the architecture of the Yamaha 250f engine allows them to produce a certain power level with high confidence in its reliability. This is a result of starting with a good platform that was designed and produced by Yamaha. Between the guys at Yamaha doing their job good, and the guys at Star doing their job good. They can produce an engine that is reliably really fast. I’m sure the guys at geico can build an engine every bit as fast as star’s guys. But the platform they are given to work with may lend itself to be less reliable at the desired power.
Anything can be done pretty easy until money is a factor. You want it light, you want it fast, you want it durable, you want it cheap. Pick 3.
Pit Row
I know J-Mart hated Bobby and the Star crew by the time he left, but I bet he'd give his left nut to be riding that bike for the rest of the summer. The Honda 250 just doesn't have the same torque.
There is zero proof of any horsepower advantage as it would show up in the production bikes on a dyno. Too many factors when building a factory 250f to say the reverse design is responsible.
What I can say for sure is yamaha riders have to clean their filters more and listen to the intake noise. Yamaha has been a horsepower company for decades, long before the latest gimmicks. Down draft is not a gimmick but you don't need a backwards engine to pull it off.
IMO if the other guys could hit it they would. Everyone was taking the same line around the outside by the second moto anyways. Amart didn't hit it one time then busted it out in the last two laps (of the first or second moto? can't remember) bc he knew he had to.
2) Not a single part in common
The engine is an excellent design and is pretty damn solid, too...which allows then to push comp ratios and revs pretty damn hard. That straight-shot intake is a damn good advantage, too.
Was called the Dream D type
1949 The company produces its first real motorcycle, powered by a 98cc a two-stroke motor. When an employee sees the first one assembled and it is ridden outside the factory, he says, “It’s like a dream.” The name “Dream” was adopted for the bike, officially known as Model D.
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