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Obviously emissions ended them. But 20 years ago Bimota brought out a 2-stroke bike that used fuel injection. Fuel wan't injected until the exhaust port closed so it didn't spew out the exhaust pipe unburned. Ran very clean & got great fuel mileage. They said a 500 twin would make 100+ hp but weigh like a 400. Well, Bimota had problems with programming, never got it right & almost went out of business. Or did & came back. Snowmobiles & personal watercraft has been using this technology 20+ years but somehow it can't be applied to motorcycles. My guess is that no one wants to roll the dice & risk going bankrupt developing a 2-stroke bike that may or may not sell. Me, I 'd love a liquid-cooled RD400. They vanished about the time I got my license to ride.
 

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I loved them, had a Yamaha RD 400. Very quick bike for its time. The down side to two stroke motors is that they didn't last as long as 4 strokes back then.
 

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The RD 400 is a lot like the XS650. They go faster as the years roll by.
They made 44 hp at 7500 and weighed 376 pounds.
The bike that replaced it was the XS400. It made 45 hp at 10,000 revs, and weighed 376 pounds. The specs claim 106 for the RD and 100 for the XS. For the average street rider both are wrong.
I raced against the RD400 years ago, and own an XS400. The XS has an electric starter, and a mono shock rear suspension.

Yamaha made 250cc and 350cc road race bikes that were very successful. A 350 won the Daytona 200. Later they made a 700cc four cylinder 2 stroke, and soon a 750cc 2 stroke. I also raced against these bikes.
Steve Baker rode one, and he was the first US world champion road racer. Not Kenny Roberts, who also rode one. But the 750 event only lasted one year, and they then went to 500cc.

The best of the bikes mentioned above, was the last of the 250cc road race bikes. They were winning in the 350 class at the IOM and other places. Mine was the last of the air cooled, and first of the six speeds.

There was a sweet RD400 at one of the bike events I went to earlier this year.

UK
 

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The RD 400 is a lot like the XS650. They go faster as the years roll by.
They made 44 hp at 7500 and weighed 376 pounds.
The bike that replaced it was the XS400. It made 45 hp at 10,000 revs, and weighed 376 pounds. The specs claim 106 for the RD and 100 for the XS. For the average street rider both are wrong.
I raced against the RD400 years ago, and own an XS400. The XS has an electric starter, and a mono shock rear suspension.

Yamaha made 250cc and 350cc road race bikes that were very successful. A 350 won the Daytona 200. Later they made a 700cc four cylinder 2 stroke, and soon a 750cc 2 stroke. I also raced against these bikes.
Steve Baker rode one, and he was the first US world champion road racer. Not Kenny Roberts, who also rode one. But the 750 event only lasted one year, and they then went to 500cc.

The best of the bikes mentioned above, was the last of the 250cc road race bikes. They were winning in the 350 class at the IOM and other places. Mine was the last of the air cooled, and first of the six speeds.

There was a sweet RD400 at one of the bike events I went to earlier this year.

UK
Some good history there UK. A couple of years ago I thought that I might be able to pick up an RD 350 or 400 at a decent price. But I was wrong, they are now pretty pricey for a nice original one.
 

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Genuine Scooter Company still sells brand new two strokes!

Their 50cc models are all twos and up until recently they were selling a licence built Indian market Vespa with a 150cc two stroke with an honest to god manual transmission. Aside from Genuine, I think Kawasaki was one of the last to sell a two stroke.

I really really want an RD350 or the "Water Buffalo" one day, but for now I'll settle for my smoky Stella and my Yamaha U7E.
 

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2 strokes are fun to ride, but not much fun to ride behind, because of the fumes. Try following one on the Toys for Tots group ride, like I did, and see how long it takes before you are ready to puke.

Direct injection would eliminate some emissions, because the crankcase would no longer be needed to act as a induction chamber for the incoming mixture, and could then be fitted with an oil pump and the same sort of cylinder oiling arrangements that 4 strokes use. That strategy could eliminate the oil burning, but it doesn't fix the poor breathing and unburnt fuel in the exhaust. To address that, you also need to add valves, which most two strokes don't have, because they use piston/port valving. Of course, adding valves also eliminates the only real benefit of the two stroke, which is cheapness. With no dedicated exhaust stroke, or intake stroke, it's hard to imagine any 2 stroke design that can perform with the efficiency of a four stroke engine. Two stroke wins at horsepower / weight, and at initial cost, but loses in every other measure, including long term economy. What kind of fuel efficiency did your two stroke bikes get, bad or worse?

I don't mourn the passing of two stroke engines at all. In the face of what we now know about our situation regarding our environment, there's no place for devices like that. They belong with the steam engines, in museums.
 

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2 stroke outboard motors used reed valves, which is a good design.
Kawasaki used carbon rotary disc valves, and CanAm used stainless steel rotary discs. The good news with the Kawasaki was, the timing of their 250 road race bike was readily available, and the shape of the carbon disc was alterable. There were 250cc production bikes getting close to 100 mph. All stock of course.

As an aside, my 250 CanAm single, could keep up with the 400cc bikes. All stock of course. I may tell all with my last few words, if I get the chance.

UK
 

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2 strokes are fun to ride, but not much fun to ride behind, because of the fumes. Try following one on the Toys for Tots group ride, like I did, and see how long it takes before you are ready to puke.
Oh please! Tell me about it!
Back in the 70s, I rode a BMW and my brother had a Kawasaki 750 three cylinder
beast (the Widowmaker). I absolutely HATED riding behind him on that thing!
Three trails of two-stroke smoke poured from that thing constantly!
(cough cough cough)
The only good part was when we hit the tight twisty roads. I could leave him
behind because that thing didn't corner worth a damn. He used to get pissed
because I could outrun him on an old BMW. LOL!!!!!
 
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And he became unpissed when he passed you like you were on a mini-bike on every straightaway :grin:

5 BMW's and so many 2 stroke street and racing bikes have had my love and admiration:grin:

My last brand new 2 stroke was a grey metallic 1978 RD400, purchased to allow me to avoid gas lines during the current Ayatola Butthola phony gas shortage:surprise: My wife would fill up our Chevy Silverado, 454 'Gas guzzler,' and I would siphon fuel as needed to allow my 72 mile, round trip commute:wink2:

If they were available right now, I would buy one in a heartbeat. The new 2 stroke oils burn clean:grin:

If you GOOGLE '2 stroke engine technology,' you will see that 2 stoke streetbikes are coming very soon.:kiss:

Sam:nerd:
 

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And he became unpissed when he passed you like you were on a mini-bike on every straightaway :grin:

Sam:nerd:
Oh yeah, that thing could pass anything on the road except a gas station.
Ridden hard, the way he rode it, it got 17 miles to the gallon. LOL!!!!
He had to stop for gas every 60 miles or so.
My BMW had a 6.3 gallon tank and got 50 to the gallon. :grin::grin::grin::grin:

P.S. One Sunday I convinced him to drive it very easy and see what kind of
mileage it got. Although it pained him greatly, he did drive it easy.
Wow! He got 27 miles to the gallon!!!!
No wonder there was a gas shortage back then. He was using it all up!
:devil::devil::devil::devil::devil:
 

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2 strokes are fun to ride, but not much fun to ride behind, because of the fumes. Try following one on the Toys for Tots group ride, like I did, and see how long it takes before you are ready to puke.

...

I don't mourn the passing of two stroke engines at all. In the face of what we now know about our situation regarding our environment, there's no place for devices like that. They belong with the steam engines, in museums.
I'm a bit of a weirdo and I enjoy the smell and fumes of two strokes and diesels. If I come into work smelling like fuel and oily smoke it's a win in my book. :grin: Girlfriend seems to enjoy it, too. :devil: Yeah, I'm probably putting myself in an early grave by willingly exposing myself to it. :plain:

It blew my mind when I saw my first Genuine Buddy on the road. I thought 50cc two stroke scooters died with the Yamaha Zuma, and yet here was this guy riding a 2017 and putt putting happily away.

That said, yeah it's probably for the best that two strokes are only in the hands of few enthusiasts and museums.
 

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That said, yeah it's probably for the best that two strokes are only in the hands of few enthusiasts and museums.
I understand what you are saying but you are totally wrong. I own a dt250 and a kdx250 and a gt185. the gt185 has a hopeless piston port design and a hopeless charging system.

so here is the review the dt250 is antique. it was the first endro and had no competition for the first 5 years. that means no design changes from '68. that means even though mine is 74 it uses 68 tech. I changed the rear sprocket so 5.5k = 60mph. It rides like the worlds biggest moped. fun turns heads but underwhelming.

the kdx '83 is slamming. totally new tech. decent porting and pipe. again changed the rear sprocket so 5.5k = 60mph. to make it legal I used Vermont to title. I make my own baja boxes so I run legal and inspected. nothing to say. it rocks.

gt185. has a screwed up charging system. it has a constant voltage dc generator with brushes and a commutator. no way to fix this. I had to swap flywheel and stator. the stock flywheel is way to heavy. runs great and I have ridden 85mph. 40mph though.

so whats the take. 2 strokes rock. they are simple and there is no feeling like hitting the power band. go with the most modern design you can get. if its 10 years old or older and 250cc or less Vermont is happy to give title and convert that 17digit vin to street legal.
Vermont has your back If you want to 2 stroke legally.

I am no museum or an enthusiast. I'm a mechanic who has learned how to jump through all the 2 stroke hoops at the dmv. any 2 stroke with a lighting coil will work because if you change to led's the total current drain is 10w. turn signals and all. easy to convert to 12v dc. my kdx was 6v ac. the rewire happens at the regulator, its easy and dirt cheap. I can help if you need.
 

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That's funny, I describe my 4 stroke single as "Putt Putt Putt". Back in the day, the noise us guys would make for 2 strokes was more like "RINGa dinga ding"
Ha! You know what, you're so right! I usually think of two strokes sounding like "ringa ding ding" too but that didn't cross my mind when I wrote that reply. :)
After a little bit of whiskey a friend once described a small 2 stroke kid's dirt bike as sounding like "Yeeeeeeeeeeeeeet!" when it's wide open throttle. I laugh every time I hear a tiny dirt bike on trails now.

so whats the take. 2 strokes rock. they are simple and there is no feeling like hitting the power band. go with the most modern design you can get. if its 10 years old or older and 250cc or less Vermont is happy to give title and convert that 17digit vin to street legal.
Vermont has your back If you want to 2 stroke legally.

I am no museum or an enthusiast. I'm a mechanic who has learned how to jump through all the 2 stroke hoops at the dmv.
any 2 stroke with a lighting coil will work because if you change to led's the total current drain is 10w. turn signals and all. easy to convert to 12v dc. my kdx was 6v ac. the rewire happens at the regulator, its easy and dirt cheap. I can help if you need.
Vermont is actually a tad different than that nowadays.

From their site:

Vermont titles vehicles (including Motorboats, ATVs, and snowmobiles) that are 15 years old or newer based on the calendar year. For example: from January 1, 2019, through December 31, 2019, Vermont will title vehicles with the model year 2005 or newer.​
Exceptions
The State of Vermont does NOT issue titles for the following:

Motorcycles with engine size smaller than 300 cc’s
Motor-driven cycles
Road-making appliances
Tractors with a loaded weight of 6,099 lbs. or less
Trailers with an empty weight of 1,500 lbs. or less
What this means is that if you have an 80s Honda Interceptor 500 without a title, you can get a registration from Vermont. Old bikes that meet the 15 year rule but are over 300cc need to have a VIN verification sent in when you send the paperwork. However, I've read that the DMV is so lazy out there that you can get away with not sending one in.

All bikes under 300cc don't get titles from Vermont regardless of age, so if you were to buy a Grom without a title they can still get you a registration. I've used this method a few times when flipping Chinese scooters.

I love my two strokes too (had a Yamaha DT175 and a Kawasaki G5 and currently have a Genuine Stella and a Yamaha U7E) but I can understand why 4 stroke technology is favored in the modern day. 4s are generally more long term durable, not much harder to work on, more economical, don't require mixing oil and fuel, and don't leave a cloud of smoke behind them. That last bit is important for folks with health problems. Like the manual transmission in cars, two stroke motorcycles are awesome but entirely unnecessary in modern society. And that's fine by me, there's plenty of cool used two strokes out there for me to play with. :)
 

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I rode a Yamaha DT1 250cc, 2 stroke enduro quite a bit when I was in the Military and with oil injection and a mild tune, it was a very nice trail and city bike. The later DT360 and 400 were much better.:smile_big:

My paradigm shift into motorcycle reality was when I first rode a Suzuki X6 Hustler, A kawasaki H1 and the king of the adrenaline rush, the H2 750cc monster bike!:surprise:

I also had a Yamaha YDS1, a YL2C, an RD200 and the RD400 all 2 strokes:smile_big:

Of course the game changed when I bought a new 1981 XS1100 and a new 1986 V-Max, which were both king of the hill for a time!:wink2:

STIHL has further developed the 2 stroke situation with their 2 stroke/ 4 stroke engine in their weed eaters and chain saws. If I remember correctly, the engines use a gas and oil mix but have a cam driven intake valve to precisely meter the amount of fuel to help cut emissions. I have 2 of their weed eaters and they work great.:smile:

Sam:nerd:
 

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My first "real" motorcycle was a 175 Bridgestone which was a two stroke. Used rotary valves and after I got the spark plug fouling problem figured out, it was fun to ride.

Don't remember what kind of fuel mileage it got, but back then fuel was only something like 20 cents a gallon and sometimes not that much.

Box of .22 longs at Wal-mart was only 50 cents. My Bridgestone was a street bike but it traveled a few miles on some logging roads. :)
 

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The Kawasaki H2 3cyl 750 2 stroke, in its day, was the fastest bike on the road.
Unfortunately, not everyone could handle the power.
Also, a lot of the motors just blew up.
But jeez, back then, they were the Magic Carpet Ride.
The Danish cops on their old BMW bikes, couldnt touch them, so they had to buy bigger bikes.
Take Care Out There
 

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The Kawasaki H2 3cyl 750 2 stroke, in its day, was the fastest bike on the road.
Unfortunately, not everyone could handle the power.
Also, a lot of the motors just blew up.
But jeez, back then, they were the Magic Carpet Ride.
The Danish cops on their old BMW bikes, couldnt touch them, so they had to buy bigger bikes.
Take Care Out There
I can vouch for it being the fastest. My brother never lost a race to anything.
A guy we knew had a heavily modified Chevelle SS that was known to be the fastest thing around.
My brother said, "I'll race ya". The guy thought he was kidding, so my brother repeated,
"I'll race ya". They raced on a deserted dead end street. I was the "flagman".
Short story, my brother was turning around at the end of the street when the Chevelle
got there. The guy couldn't believe it and asked "What did you do to it?" Of course
he didn't believe it when my brother said, "Nothing, it came from the factory like that".
I don't know how my brother survived owning that thing.
I only rode it once. It scared the **** out of me. It was dangerous with a capital "D".
Handled terrible. Even moderate acceleration pulled the front wheel off of the ground.
It could wheelie in every gear.
 
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