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![]() This is the Ossa 300i fuel-injected enduro bike. It was developed in 2011, but was not sold in the USA. The injector is dead center in the photo. Ossa was bought by Gas Gas last year and Gas Gas declared bankruptcy and was sold to Torrot of Spain—no word on the fate of Ossa. ------------ Dear MXperts, Why are the manufacturers that make two-strokes (KTM, Yamaha, Gas Gas, Husqvarna and TM), dragging their feet on putting fuel injection on their smokers. It would solve the jetting issues forever and produce even better bikes. What’s the hold up? The first question is how much do you want the price of two-strokes to go up? The second question is how much weight are you willing to gain on your two-stroke? The third question is what’s so hard about changing a jet occasionally? The major manufacturers have fuel-injected two-strokes sitting in the R&D departments that could be released tomorrow if the world demanded it — but let’s not put our faith in the mob majority of the modern world. The current two-stroke is simple, light and relatively inexpensive. The reason that KTM, as an example, doesn’t want to fuel-inject their two-strokes, at this time, is because they will gain 5 pounds, the price will go up a couple hundred dollars and the consumer will not be able to cure his woes with minimal garage tools. KTM will offer fuel-injected offroad bikes in the future to meet the stringent new Euro-4 emission rules (as for now they have stopped selling 125cc two-stroke offroad bikes in Europe). It’s important to note that fuel-injected bikes do not produce more power than carbureted bikes — just the opposite. What they do produce is a broader, easier to use and flawless delivery of just the right amount of fuel for the X’s and O’s of the ECU. And they will idle like a kitten. However, motocross bikes often need extra fuel for an upcoming situation and that is what a carburetor is great at providing. It doesn’t stream fuel electronically via a pump, it draws fuel in via the demands of the suction created by the engine itself. Carbs are true-to-life “on demand” fuel systems. Read more: http://motocrossactionmag.com/news/a...ted-two-stroke |
Originally Posted by Slick
(Post 4167310)
AFAIK, There is an Australian company called Orbital that has already developed and tested a FI system on Aprilia RS250, and this was ages ago. -Slick |
Originally Posted by Slick
(Post 4167310)
AFAIK, There is an Australian company called Orbital that has already developed and tested a FI system on Aprilia RS250, and this was ages ago. |
Orbital came up with a method of injecting the fuel/oil mix directly into the cylinder head – the DiTech system – (as opposed to upstream of the valves in a fuel-injected four-stroke) and this breakthrough, combined with some sophisticated electronic engine management has revolutionised two-stroke engines. As an example, when I toured the Perth facility, Orbital engineers demonstrated that a DiTech engine would run quite happily on the emissions of a normal two-stroke. As an aside, the system also allows engineers easily to tune engines to various power curves to suit different applications. |
Anyway, Aprilia chose engine characteristics that shocked the scootering world when the first model came out. I was lucky enough to ride one and found I could carry a comfortable 110km/h on a freeway – from a 50! Later models were detuned a bit to comply with various registration requirements, but the power was lurking, waiting to be released. The upside of the retune came in fuel economy, with as little as 2L/100km claimed in fuel usage but, more importantly, up to 60 per cent less oil consumption – with service intervals of 12,000km. So that keeps the bureaucrats happy and puts more change in your pocket, but it’s still an expensive 50, right? |
Originally Posted by sudev
(Post 4167228)
Very interesting. 2 stroke are free revving as there is no valve train. Technically ok need not be premixed. Remember Yezdi King? Injection means lots of tuning possibilities |
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