Two-stroke motorbikes

[Zedder]

Article from the NZ Herald: http://www.driven.co.nz/news/lifestyle/fall-of-the-mighty-2-stroke-motorcycle/?ref=nzh_networkfooter

[ellipsis]

...I'd have one of those 350 Jawas...would sit well beside the Sportster and the Velocette...

[GrayWolf]

...I'd have one of those 350 Jawas...would sit well beside the Sportster and the Velocette...

used to have them in the UK as 'winter' bikes, rugged, torque rather than HP {they put single adult velorex sidecars on them too} if you slid off? Usually it was just bent footpeg, bent bars, straoghten out with a bit of scaffold tube....

They are closer in the way the pull, to the old T500 suzuki than an RD or GT

[roogazza]

As young fellas of about 16 I had a YDS3 Yam and my mate had a 350 Jawa. Very slow idle on the Jawa.One morning it was idling in the driveway,he's revved it and let out the clutch and rocketed backwards ! The slow revving idle turned , and the motor started running backwards !!!
Funny as a fit,we were rolling on the ground laughing.
It had 16 inch wheels and as my mate rode it , it was quite fast round corners ?? :wacko:

[george formby]

used to have them in the UK as 'winter' bikes, rugged, torque rather than HP {they put single adult velorex sidecars on them too} if you slid off? Usually it was just bent footpeg, bent bars, straoghten out with a bit of scaffold tube....

They are closer in the way the pull, to the old T500 suzuki than an RD or GT


My mate used one for years in Scotland. It was the only thing that would start when the temperatures plummeted and low enough to use your feet as outriggers in the snow.

[F5 Dave]

Ignores the tens of thousands of off road 2 strokes in production.

The TS250 looks fantastic. I'd love one with the rounder hole heatsheild on exhaust. Haven't found one in my price range (charity?) Yet.

[george formby]

Ignores the tens of thousands of off road 2 strokes in production.

The TS250 looks fantastic. I'd love one with the rounder hole heatsheild on exhaust. Haven't found one in my price range (charity?) Yet.

I posted in the "other" 2t thread that popped up yesterday after a wee play on my DT. The fun factor and character is off the charts on twisty roads and gravel. Common comments #1 "is that a 2t? Don't see them very often"

[pritch]

My one and only 2 stroke was a Yamaha RT2. Perfect for getting around the Wellington hills quickly and, it transpired, far better for navigating the Akatarawa Rd than a VFR. A bloody awful tourer though, but that's not what it was designed for. If I was heading out of town there was a brief stop at Porirua to swap the plug lead to the harder plug.

I think it's in the movie "Faster" that the 2 stroke is described as a crude but effective device. Sounds about right.

[F5 Dave]

Far more elegant solution than a foul stroke.

Off riding my GasGas300 tomorrow. Lighter and of course better spread of power compared to peaky 4 stroke.

There's about 6 in my riding group.

[flashg]

Far more elegant solution than a foul stroke.

Off riding my GasGas300 tomorrow. Lighter and of course better spread of power compared to peaky 4 stroke.

There's about 6 in my riding group.
Something I struggle to get my head around. My injected WR 450 with the Aussie map wants to rip my arms off from idle to max rpm. My Beta RR300 2t never feels like it has anywhere near that sort of power. Yet my son on the Beta and me on WR from standing start, race across paddocks and the Beta is beside WR all the way. No advantage to either (we're both 78kg)and the Beta runs on 91octane, WR 95 octane. The thing is the 2t never wants to rip my arms off at any time. This I don't get, but I like it.

[Zedder]

Ignores the tens of thousands of off road 2 strokes in production.


A mate in the UK told me Honda have recently published a patent for a new fuel injected two-stroke which could mean the return of road 'bikes as well.

[sidecar bob]

Something I struggle to get my head around. My injected WR 450 with the Aussie map wants to rip my arms off from idle to max rpm. My Beta RR300 2t never feels like it has anywhere near that sort of power. Yet my son on the Beta and me on WR from standing start, race across paddocks and the Beta is beside WR all the way. No advantage to either (we're both 78kg)and the Beta runs on 91octane, WR 95 octane. The thing is the 2t never wants to rip my arms off at any time. This I don't get, but I like it.

One is using torque to move, the other horsepower.
Torque rips your arms out, horsepower dosent.

[jellywrestler]

Far more elegant solution than a foul stroke.

Off riding my GasGas300 tomorrow. Lighter and of course better spread of power compared to peaky 4 stroke.

There's about 6 in my Vapers group.
fixed it for you

[flashg]

One is using torque to move, the other horsepower.
Torque rips your arms out, horsepower dosent.
Thanks sidecar bob, Yamaha claims 47hp for this WR, and if I remember correctly, Beta claims about 55hp, so that kinda makes sense. Interesting indeed.

[pritch]

A mate in the UK told me Honda have recently published a patent for a new fuel injected two-stroke which could mean the return of road 'bikes as well.

If by recent you mean mid 2015 that has been mentioned in the other thread, but it would take a huge turnaround by Honda who were instrumental in getting the 2 stroke classes dropped from racing.

http://newatlas.com/honda-two-stroke-with-fuel-injection-patent-filing/38529/


Now that KTM are expanding their two stroke range it's probably fair to assume the other manufacturers are watching with interest.

[Zedder]

If by recent you mean mid 2015 that has been mentioned in the other thread, but it would take a huge turnaround by Honda who were instrumental in getting the 2 stroke classes dropped from racing.

http://newatlas.com/honda-two-stroke-with-fuel-injection-patent-filing/38529/


Now that KTM are expanding their two stroke range it's probably fair to assume the other manufacturers are watching with interest.


This article dated 18/3/2017, states Honda published a patent, not just filed one: https://www.morebikes.co.uk/20748/scoop-hondas-secret-plans-two-strokes-are-back/

[pritch]

This article dated 18/3/2017, states Honda published a patent, not just filed one: https://www.morebikes.co.uk/20748/scoop-hondas-secret-plans-two-strokes-are-back/

Looking at the engine it's an unlovely lump. Very tall and with a push rod exhaust valve, the later article picks it to be an industrial engine.

The KTM engines apparently use transfer port injection and should be in bikes later this year.
https://ultimatemotorcycling.com/2017/03/16/ktm-fuel-injected-two-stroke-engines-announced-6-fast-facts/

[Zedder]

Looking at the engine it's an unlovely lump. Very tall and with a push rod exhaust valve, the later article picks it to be an industrial engine.

The KTM engines apparently use transfer port ignition and should be in bikes later this year.
https://ultimatemotorcycling.com/2017/03/16/ktm-fuel-injected-two-stroke-engines-announced-6-fast-facts/


The article about the "industrial" engine was an earlier one, 2015. The design has been upgraded.

I note in the article, the fuel injected KTM two-stroke was expected to be "expensive and heavy as a four-stroke engine"... "which could well kill demand".

[F5 Dave]

So, a 450 vs a 300. And you struggle to comprehend that. . . ??

[Scubbo]

think it's great, i'm hoping more follow suit, be nice to see some innovation in the engine again instead of just driver aids sold as next years new bike

[GrayWolf]

My mate used one for years in Scotland. It was the only thing that would start when the temperatures plummeted and low enough to use your feet as outriggers in the snow.

had a mate who went to Uni at St Andrews.. had an MZ ETZ250.... used to thrash it all the way from London to St A's ride round Scotland, ride it home, term after term. about 80mph flat out,,,, but always started regardless of temperature. The East Europeans certainly knew how to build vehicles that were basic and rugged that start in the cold.

I'd also have another Jawa for a 'fun' bike....

[flashg]

So, a 450 vs a 300. And you struggle to comprehend that. . . ??
Its the dyno in my butt and arms that tells me the Beta doesn't have the grunt of the WR (they are so different) But it really does, as they arejust as fast as each other. The Beta is less tiring after many hours of riding, I'll say that.

[george formby]

Its the dyno in my butt and arms that tells me the Beta doesn't have the grunt of the WR (they are so different) But it really does, as they arejust as fast as each other. The Beta is less tiring after many hours of riding, I'll say that.
I've only had a brief shot on a 450 4t and I was tired just starting the bloody thing. About as much use as a chocolate fireguard for my type of riding - not fast.
I would lurve to have a shot on a Beta 300 rr or Xtrainer. Much more my cup of tea, nice and agile.

[F5 Dave]

Been out riding my 300 GG today. I love that bike, it makes me grin while riding it. First lap was a bit slippery up the hills and I spent time just slowly torqueing past people scattered about the place. If I could steer around them I was fine. The tublis rear helps, but so does flywheel weight and jetted and head reshaped 300cc. Fantastic.

People remember riding some clapped out small cc 2stroke with woeful std jetting which goes burble burble Waaaahaa and form the idea that 2 strokes are peaky. Err, no.

[george formby]

Been out riding my 300 GG today. I love that bike, it makes me grin while riding it. First lap was a bit slippery up the hills and I spent time just slowly torqueing past people scattered about the place. If I could steer around them I was fine. The tublis rear helps, but so does flywheel weight and jetted and head reshaped 300cc. Fantastic.

People remember riding some clapped out small cc 2stroke with woeful std jetting which goes burble burble Waaaahaa and form the idea that 2 strokes are peaky. Err, no.

Exactly why i want a shot of a modern 2t. My old CRM will tractor along at ridiculously low revs, adamantly refusing to stall and a touch of clutch when it comes on the pipe maintains grip. Really nice to ride but heavy. My DT is set up for max Waaaaaaaah on gravel and tar seal. I have no interest in trail riding it anymore, it's not happy unless your up it.

[MarkW]

My DT is set up for max Waaaaaaaah on gravel and tar seal. I have no interest in trail riding it anymore, it's not happy unless your up it.

Are you a big girl or what? Last time we were out you gave me the DT to trail ride all day. And it only broke down when YOU were riding it home.

[flashg]

Any of the modern 300 2t would be good for you. I've been told the Beta is popular for shorter people as its got the lowest seat height

[pete-blen]

People remember riding some clapped out small cc 2stroke with woeful std jetting which goes burble burble Waaaahaa and form the idea that 2 strokes are peaky. Err, no.



my little 79 Montesa 125 H6 is a dam hard bike to ride on todays standards...
powers between 6 to 10 grand... it's either lifting the wheel & spitting rocks out
or bogging down till yer drop it a gear or two.. but when it's on the pipe, dam
it's fun...only weighs 80kgs....



..

[Delerium]

Emissions laws will have stopped them in western countries wont it?

[pritch]

Not entirely surprising, but Husqvarna are at it too.

http://www.asphaltandrubber.com/bikes/husqvarna-fuel-injected-two-strokes-2018-enduro/#more-132238

[Cosmik de Bris]

Emissions laws will have stopped them in western countries wont it?

Yeah but with direct injection and other modern stuff they might be able to beat the regs; if there is a will.

[Zedder]

Yeah but with direct injection and other modern stuff they might be able to beat the regs; if there is a will.


Yes. As I understand it, direct fuel injection for 2-strokes has already demonstrated an 80% reduction in CO and hydrocarbons plus 50% reduction in particulate matter and 40% less total CO2 emissions.

[Dblakem1]

Ignores the tens of thousands of off road 2 strokes in production.

The TS250 looks fantastic. I'd love one with the rounder hole heatsheild on exhaust. Haven't found one in my price range (charity?) Yet.

Still by a brand new TS185 Suzuki in Japan - and in UAE I believe...😀

[Crasherfromwayback]

The KTM engines apparently use transfer port injection and should be in bikes later this year.
https://ultimatemotorcycling.com/2017/03/16/ktm-fuel-injected-two-stroke-engines-announced-6-fast-facts/

I hope they're absolutely fantastic too. Might make Japan get back into them. One can only hope.

[Bruce Lee]

Reminiscing my old RGV250. Had a Pepsi race replica pre banana arm, jeez that was fun

[Crasherfromwayback]

Reminiscing my old RGV250. Had a Pepsi race replica pre banana arm, jeez that was fun

Awesome looking bike those. I'd love one of my old KR1SPs back that's for sure.

[pritch]

Couldn't decide whether to put this link in the bike porn thread or this one. I used to be indecisive but now I'm not so sure?

No drawings this time, pics, lotsa pics. For those lusting after the return of two strokes, knock yourself out.

https://www.asphaltandrubber.com/bikes/ktm-250-300-exc-tpi-two-stroke-mega-gallery/#more-134834

[sidecar bob]

Ive managed to pick up a low mileage alloy frame RZ500 recently.
Im fairly confident we wont be seeing new bikes anything like them ever again.

[eelracing]

2 x pots please V,Tandem,parallel I don't care.Chuck it in a light roadgoing chassis with WP suzzies.
Leave out the electronic control shit,keep it cheap(ish) and watch it sell bucketloads.


The Japs'll follow like drones.

[Crasherfromwayback]

2 x pots please V,Tandem,parallel I don't care.Chuck it in a light roadgoing chassis with WP suzzies.
Leave out the electronic control shit,keep it cheap(ish) and watch it sell bucketloads.


The Japs'll follow like drones.

That we can def agree on!

[denefoster]

2 x pots please V,Tandem,parallel I don't care.Chuck it in a light roadgoing chassis with WP suzzies.
Leave out the electronic control shit,keep it cheap(ish) and watch it sell bucketloads.


The Japs'll follow like drones.

There is a class in the US, Super Single if it's still going, that produced badass rides like http://www.cycleworld.com/2007/09/13/honda-crf450x-super-single-roadracer-first-look

I'd kill for a fancy DI 2smoke gussied up like that.

And on second look, http://www.racetech.com/page/id/61 has kits for sale

[mulletman]

This looks good

http://www.crash.net/motogp/news/247548/1/suter-500-could-match-motogp-times.html