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well played sir!
We've had 100s and its simpler than carburetors.
300 bucks more.
This was in 1994. Crisp running all day night it didnt matter.
Today its better.
What amazes me is nowadays with the internet people are less educated than ever.
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Its like the three monkeys. See no evil hear no evil speak no evil.
If no one seen the smoke smelled it or heard it non moto people would still have a problem with a bike.
Its like the guy who drove his prius from Indianapolis to chicago 3hrs because it was better on the enviroment than flying there.
Then I told him the plane still went and with an empty seat so he polutted more by driving than flying.
LOL, I dont know whether to bust out laughing or shake my head in disgust.
Or both.
In marine outboards, DI 2 strokes are a good engines. However they aren't much better or worse overall than 4 strokes.
But to make it work and meet CARB emissions you need stuff like a lean oil injection system and a scavenging blower. You know, all the extra stuff you get on your fuel injected snowmobiles and outboards.
Not bashing 4 strokes but numerous racers having problems with 4 stroke motors and we're complaining about cost. I know they're good, fast and smooth but don't want the headache at my age.
In fact, if you think a simple EFI system on a 2 stroke does little, it just proves you've never seen it and how clean it is.
Both Polaris and Suzukis are damn near as simple as a carb. For the layman, its a simple as starting a car and ride.
Over half our FI stuff is premix, BTW.
And dont forget, CARB doesnt govern closed course competition machines. AKA Dirt bikes. Only if ridden on public lands.
A scavenging blower? LOL. Where do you guys get this shit?
Im running a turbo with about 8 conservative Lbs of boost, but that has nothing to do with fuel and exhaust scavenging or port timing or anything else.
Please explain to me where all this complexity is? Because there isnt much here that looks complex to me.
165 HP Stock with a few CPU tweaks. Its been Detuned since.
And again, where is all this complex stuff? Stuff no mortal could ever understand?
And those are damn near the same throttle bodies that were used in 1992 by Polaris (Fuji) and then Suzuki.
And with biodegradable full synth oils, well, they have most of 2 strokes burning cleaner with less emissions than comparable HP 4 strokes.
For example a 600 cc 2 cylinder 2 stroke VS a 4 cylinder 1,000 cc 4 stroke. (About the same HP Class)
KTM has had a prototype DI two stroke around for a few years now. They are on record as saying that a lot of the benefits of current two strokes are less clear with a DI design.
Pit Row
Dual stage rail injection system
Electronic oil injection pump
Whole system relies on computer control...
Not exactly your simple dirtbike engine.
Don't me wrong, I'm not saying FI (or DI) two strokes can't work, because clearly they can. And they can sit alongside 4 strokes as competitive engines.
What I'm saying is that once you start adding all the bits to make them that way, it's not a "no brainer" engine choice against a comparable 4 stroke.
This design is likely adaptable to motorcycles, it's not much more complex than the EFI of a modern CR/KX/RM etc., and compared to the valvetrain of a 4T... It would take R+D dollars to develop it for another application and that's probably a stumbling point. Would make for some fun PWC applications as well. The piston design is one of the neatest parts to accommodate different injection points.
Engine/Tech link Link
2 DI or EFI for that matter has been available batteryless since 1995 on everything except outboards for obvious reasons.
3 EFI has NEVER mixed fuel and oil in the same injector except on a few outboards and its RARE, and typically the main bearings get their own oil line with one going to the crankcase.
The CAT engine mixes a tiny amount in the rail to help aid top and bottom end bearings.
It also doesnt have a return line to the tank.
There is also lines going to the main bearings that are oil only
What is the advantage to putting Fi on a 2-stroke? What problem are you trying to solve that is worth the hassle? We've already established that there are no emissions regulations pertaining to closed course vehicles so convince me why I should want to change my perfectly running, hassle free carb'd YZ125 and YZ250.
Just to say they are "updated"
Don't worry, your Yamaha will run for the rest of your life if taken care of properly.
While others will bitch and complain about it being old and not "updated"
Because its not the same in January as July.
Also, so you can ride it anywhere, sticker it for off road on public lands, and go from 110 in Phoenix to Snow in Flagstaff and not do a damn thing but ride it.
And have a smoother powerband, and more top end power, and, well, shit, the list is long.
Oh, and you could big bore it, Pipe it, Port it, and have it dialed with just a few clicks.
FI 2 strokes are a crispness few get to realize. Its like your "perfectly jetted" bike on a cold day runs just that little bit better.........only its like that all the time.
The Boyesen article on Trapping is an amazing read also.
you should just listen to others once and a while, instead of thinking you know it all. You clearly don't know much about modern production 2-stroke engine packaging or design.
"What I'm saying is that once you start adding all the bits to make them that way, it's not a "no brainer" engine choice against a comparable 4 stroke."
- is that why every manufacturer makes 4-stroke sleds, yet they only make up less than 10% of sales? if you want a big bump sled or a deep snow sled (i.e. the lighter the better) 2 strokes are a no brainer.
now hold on to your hat Ando, 'cause your not going to believe this. Sherco's EFI set-up added 1.1lbs and $100 to the price of the outgoing model (2013my). a new oem tire choice could have a greater effect than that.....
I would say that kind of makes your point irrelevant. Keep comparing multi cylinder sleds to bikes though, if it makes you feel more relevant.
As far as the Arctic Cat laydown motor goes I'm not sure who owns the patent to the DI system since Arctic cat uses Suzuki motors. The Arctic Cat system has been proven and reliable I have seen people get 7,000-11,000 miles without even opening the 700 motor. Sleds pretty much had to go to DI because none of the manufacturers had a wide range of 4 stroke motors besides Yamaha. Basically because of DI 2 strokes were able to stay in snowmobiles since they could easily meet emissions and still retain a high performance motor. My sled is a 2007 carb and mid range was lean from the factory to meet emissions it caused a lot of burn downs because they were trying to meet the emission standards for 2007.
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