Two Stroke direct injection : 2-stroke comeback ?

5 replies to this topic
  • Ynahg

Posted January 25, 2002 - 04:41 AM


Recently Aprillia has developped a small 2 stroke direct injection engine (50cc scooter). These type of engines seem to have a lot of future . Less feul consumption, less oil and -80% exhaust emissions. They can be compared to two stroke diesel engines, the scavenging is done with air and not with air/fuel mixture.
Could this be the comeback of the two strokes
Don't forget a 2 smoke will allways stay twice as powerfull as a 4-stroke with the same displacement. A WR 426 with 110 bhp !!!!!!??? :)



  • lewichris

Posted January 25, 2002 - 05:35 AM


snowcats use oil injectors. you dont have to mix gas at all. they still smoke like hell. but nothing like 0-100 in 4 sconds. I will always love that.

  • jamracing

Posted January 25, 2002 - 06:02 AM


Aprillia is going in the right direction, but as far as high performance two strokes, direct fuel injection is still dodgy. Bimota went into enormous debt when their v-twin 500cc injected two-stroke failed to deliver the proper get-up-and-go, and the fuel delivery system was the primary culprit. You don't want a 320 pound, 500cc two stroke (making around 115 hp) with a jerky powerband :) . Sure it was able to pass emissions, but it ran like crap. They slapped carbs on it, and it made 10-15 hp more...
My point is that a machine that will be working in one RPM range (scooter, watercraft) doesn't need a sophisticated system. A motorcycle, on the other hand, needs a far more complex injection system.
My .02

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  • powerthirstypsyco

Posted May 28, 2007 - 07:13 PM


To have injection you have to have a fuel pump,more wires,power to run the pump,plus the tecnology and sensors to tell it when to inject the fuel- eventually in trail dirt bikes and stuff like the Wr or TTr but i dont think it will ever be in the MX stuff imo but you never know alot of ppl like 2 strokes includeing me- maby that will bring them back... i heard that after 07 or somthin only yammi will make 2 strokes

  • windaddiction

Posted May 28, 2007 - 09:11 PM


They have had these new 2 strokes in marine engines for a few years now.... I have heard very good things about them. I too love 2 smokes my sister has a 1996 dt200 yammi one fo the funnest lightest bikes ive ever ridden!

  • ajetmech

Posted May 28, 2007 - 11:40 PM


I know what you are saying about 2 smokers being fun. Every once in a while I jump on my boys yz 125 and have a blast. I would not mind picking up a old CR500 to hal my fat butt around every once and a while. But when the fun is done nothing beats how easy and reliable a 4 stroke is.


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