Two Stroke Motocross
Two Stroke Motocross Forum => General Two Stroke Talk => Topic started by: Chris2T on July 23, 2010, 06:49:00 AM
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Observe the two sets of top end photos, one from a 2007 CRF450R and the other a 2007 CR250R. I counted 118 parts for the 4 stroke and 40 for the 2 stroke. It's a stark reminder that there's up to 68 more parts for a 4 stroke top end rebuild that a company can make profit on. And some of those are VERY expensive parts. It's a business decision that is keeping the 4 stroke juggernaut rolling. Perhaps the somewhat more parts-intensive Direct Injected 2 stroke motors will turn things around?
(http://img.photobucket.com/albums/v380/freespiritrider/2007CRF450RCylinder.jpg)
(http://img.photobucket.com/albums/v380/freespiritrider/2007CR250RCylinder.jpg)
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sorry for the different image sizes, i took these off of bikebandit.cm
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I admire your determination... you actually counted all the parts?? You're hardcore.
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I counted 123 and 62.
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Sounds like everyone in the building (virtual building) is hardcore!
But, although the four-stroke was surely a business decision, I think it was a bad one given how many wasted resources these businesses have locked away in warehouses. They would never be able to get away with it without a displacement handicap to create an incentive for people to buy these overcomplicated pigs.
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I would not count all the parts (who cares about a washer here or there), I would only count moving parts. I would then determine what lubercation each of those moving parts has, and the tollerances of all the bearings related (i.e. x rpm in oil or whatever), the reason I even say that is that likely the smaller bearings which might be moving the valves in the 4 stroke could have less life than the larger crank bearings. The larger crank bearings in the 4 stroke will be sitting in motor oil, etc.
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If you throw in the total of the parts within even a simple 2t carb, I think you might even reduce the Number of parts on a DFI'd 2t. I'm of course, fudging a hell of a lot, and just choosing to look at the ECU/ CPU , sensors and injector itself as single unit items........... but, we don't /can't get CDIs, ECUs in component break down (into parts) form , and injectors / sensors, to my limited knowledge, are also made as / regarded as, non break down items.
Mind you, there are a hell of a lot of ways of doing a DFI 2t. Lets hope the blokes who design them, believe in the KISS concept.
The thing to keep in mind, is that it's not a good business decision to make bikes that people don't want / can't afford to keep running.
Cripes, even Bill Gates has just invested 26 million in the opposed piston 2t. If he can be behind the cleanliness , simplicity and efficiency of a 2t, there's hope for 2t acceptance amongst the great unwashed.