2010 yamaha s.h.o. 200-250 4strokes

[baja200merk]

Yep, thats about when 2 stroke outboard technology stopped as far as I'm concerned.

WHAT

18yrs later they are makin 380hp out of a v6 3.3 2 stroke yami which is more reliable and twice as efficient so i have no clue where in the hell you figure 2 stroke technology stopped

[stan merck]

WHAT

18yrs later they are makin 380hp out of a v6 3.3 2 stroke yami which is more reliable and twice as efficient so i have no clue where in the hell you figure 2 stroke technology stopped

Sure people have learned a little more on porting but take away the direct injection and its the same old fixed ported eng. The 2 stroke by now should of had variable intake and ex ports. Even MX bikes the technology hasnt changed in 20 yrs.

[stan merck]

I am not saying direct injection isnt an advancement but more of an adaptation to an existing engine. Besides direct injection adds very little if any power, maybe a little bit of lowend power. More efficient, sure but at higher rpms you cant inject fuel with the ex port closed anyway, not enough time to fill the cylinder.

[stan merck]

Look at the old in line 6, at its pinnacle of development: 180 to 190 hp from 1.6 liters, about the same as the Yamaha in the given example from an archaic non loop charged engine.

[DoktorC]

Look at the old in line 6, at its pinnacle of development: 180 to 190 hp from 1.6 liters, about the same as the Yamaha in the given example from an archaic non loop charged engine.

190hp inline that runs on pump gas and you can drive all day...and will put a bass boat on plane...oh and is 2 star compliant??? This I gotta see

Still poor output/displacement for a 2 stroke in general...

[powerabout]

Yep, thats about when 2 stroke outboard technology stopped as far as I'm concerned. Those twin pinion cases were big $$$.

I'd like to see it with E-tec injection

[baja200merk]

190hp inline that runs on pump gas and you can drive all day...and will put a bass boat on plane...oh and is 2 star compliant??? This I gotta see

Still poor output/displacement for a 2 stroke in general...

no chit

I guess some one figured something out in 08... I thought 2 stroke tech was over all over 20 yrs ago?
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/qpoEjY7KDdo&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/qpoEjY7KDdo&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

[powerabout]

The Jap car makers have done quiet a bit of reasearch and built many test engines that are for modern 2 strokes for cars.
They have wet sump, exhaust ( conventional poppet) valves in the head and supercharged.

I think when Ford evaluated 'Orbital engines' 3 cyl 2 stroke, it did many things better than the 4 stroke.
They are still emission compliant today.
All I ever heard was they thought the consumer wouldn't go for it?

[powerabout]

Look at the old in line 6, at its pinnacle of development: 180 to 190 hp from 1.6 liters, about the same as the Yamaha in the given example from an archaic non loop charged engine.

trouble was it sucked more fuel than a 500ci nitro drag car

[stan merck]

190hp inline that runs on pump gas and you can drive all day...and will put a bass boat on plane...oh and is 2 star compliant??? This I gotta see

Still poor output/displacement for a 2 stroke in general...

Exactly, the output hasnt changed much. Loop charging allows higher hp on pump gas.

[Instigator]

no chit

I guess some one figured something out in 08... I thought 2 stroke tech was over all over 20 yrs ago?
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/qpoEjY7KDdo&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/qpoEjY7KDdo&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

I love the chit eatin grin on the guy holding the bottle when the dyno operator asks "what's next?"

To the 2 stroke nay sayers, think if Merc/BRP/Yammi had a budget of a car co. for development. Remember that almost all the current 4 stroke O/B tech was robbed from car motors after billions of dollars in R&D.
Also remove the tree huggers/EPA trying to force car motors down our throat while refusing to listen to or accept logical/actual 2 stroke capabilities.

On the difference in R&D budgets (2 stroke Vs 4) consider a story I read about Mercruiser going to GM to try and halt their elimination of the 454.
GM's reply to Merc was that Mercs total anual volume of 454 consumption equaled one weeks (as I recall) production for GM!

Lastly, look at every rule book for every motor sport on the planet and the difference in motor displacment limits between 2 strokes and 4. Normally about 2:1.
The cool, new 450cc Moto Crossers race in the same class as 250 2 strokes. F-1 bikes went to 1000cc 4 strokes from 500cc 2 strokes.
Wonder which technoligy is supposed to win

[DoktorC]

Lastly, look at every rule book for every motor sport on the planet and the difference in motor displacment limits between 2 strokes and 4. Normally about 2:1.
The cool, new 450cc Moto Crossers race in the same class as 250 2 strokes. F-1 bikes went to 1000cc 4 strokes from 500cc 2 strokes.
Wonder which technoligy is supposed to win

Ok...so that vid was a 1700+ 2 stroke on N2O....

Here's a baby 1000cc 4 stroke with a little boost .

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/LFDL01akqpg&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/LFDL01akqpg&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

[stan merck]

To me the future is the 4 stroke camless eng. With that they can even through software have the eng run as a 2 stroke for power when needed and as a regular 4 stroke perfectly cammed for every rpm.
http://www.halfbakery.com/idea/Camless_20engine

[blkmtrfan]

To me the future is the 4 stroke camless eng. With that they can even through software have the eng run as a 2 stroke for power when needed and as a regular 4 stroke perfectly cammed for every rpm.

I too think that is the future and have thought so for a couple of decades

[stan merck]

I will always love 2 stroke engs, but fixed ports cut into a cylinder and burning oil just isnt going to work for the future.